### Description
<!-- Describe your changes. -->
Update various test projects to .net8 from EOL frameworks.
Replace the Xamarin based Android and iOS test projects with a MAUI
based project that uses .net 8.
Add new CoreML flags to C# bindings
### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
Remove usage of EOL frameworks.
### Description
1. Update donwload-artifacts to flex-downloadartifacts to make it eaiser
to debug.
2. Move the native files into Gpu.Windows and Gpu-linux packages.
Onnxruntime-Gpu has dependency on them.
3. update the package validation as well
4. Add 2 stages to run E2E test for GPU.Windows and GPU.Linux
for example:

### Motivation and Context
Single Onnxruntime.Gpu Package size has already excceded the Nuget size
limit.
We split the package into some smaller packages to make them can be
published.
For compatibility, the user can install or upgrade Onnxruntime.Gpu,
which will install Gpu.Windows and Gpu.Linux automatically.
And the user can only install Gpu.Windows and Gpu.Linux directly.
### Test Link
1. In ORT_NIGHTLY
2. Install the preview version in nuget-int. (nuget source:
https://apiint.nugettest.org/v3/index.json)
---------
Co-authored-by: Scott McKay <skottmckay@gmail.com>
Add Xamarin support to the ORT nuget packages.
- Update C# code to support Xamarin builds for iOS and Android
- refactor some things to split out common code
- include iOS and Android ORT native shared library in native nuget package
* Merge CPU/GPU nuget pipeline
* Include TensorRT EP libraries into existing GPU nuget package pipeline
* modify to use correct YAML
* Modify for test
* modify for test
* Add depedance
* Add depedance (cont.)
* modify for test
* Add create TensorRT nuget package
* modify for test
* modify for test
* Merge CPU/GPU nuget pipeline
* Include TensorRT EP libraries into existing GPU nuget package pipeline
* modify to use correct YAML
* Modify for test
* modify for test
* Add depedance
* Add depedance (cont.)
* modify for test
* Add create TensorRT nuget package
* modify for test
* fix merge bug
* code refactor
* code refactor
* modify for test
* modify for test
* modify for test
* modify for test
* modify for test
* modify for test
* cleanup
* modify for test
* fix bug
* modify for test
* refactor
* fix bug and test
* Modify for test
* Modify for test
* Modify for test
* Modify for test
* Prepare for PR
* Prepare for PR
* code refacotr from review
* Remove naming 'Microsoft.ML.OnnxRuntime.TensorRT' to avoid confusion
* Add linux TensorRT libraries
* Remove redundant variable in YMAL
* revert file
* undo revert file
* Modify regular expression so that it can capture the correct file
* Remove newline at end of file
* small fix
* Revert to CUDA11.1 on Windows
* Add unit tests for nuget package on Linux
Co-authored-by: Changming Sun <chasun@microsoft.com>
Merge CPU/GPU nuget pipeline. The old GPU nuget pipeline will be only for DML.
TODO: the result GPU package contains PDB files for some of the DLLs, but not all. It is due to the refactoring of CUDA EP to pluggable DLLs. At that time we forgot to copy the PDB files. However, I can't add them in now. Because currently the package is already 220MB large. If the missed PDB files were added, then it will be oversize. nuget.org doesn't accept >250MB packages.
* WIP: Re-enable x86 .NET testing in Release pipelines
Enabling x86 testing will make sure that ORT packages doesn’t break x86 projects of customers
* Remove setting some env variables
* Comment out a test failing on x86 builds
* More changes
* Minor fix
* More changes
* More changes
* s
* s
* s
* Revert minor change
* More changes
* More changes
* More changes 2
* explicitly set platform target
* Delete bin and obj folders
* Clean output dirs
* Add back TargetFramwork
* Disable x86 .net framework tests
* Skip x86 tests in MKLML pipeline
* Simplify linux gpu pipeline
* Refactor win-gpu-ci-pipeline.yml
* Set cuda environment variables for testing and version
* Remove variables from starter script
* minor fix
* Add GPU Nuget pipeline
* Set DisableContribOps environment variable for Linux package tests
* Add ESRP tasks
* Add ESRP signing templates
* Test out hardcode value of ERSP
* Test out hardcode value of ERSP
* Test out hardcode value of ERSP
* Test out hardcode value of ERSP
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test out variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* test variable expansion
* update cpu pipeline to conditionally esrp sign
* Set C# GPU tests to run only if env var is set
* Refactor for easy parameter passing
* refactored esrp templates
* remove variables from template
* Add packaging variables back to pipelines
* update C# for cuda 10
* Merge vars ana parameters for gpu pipeline
* remove vars from mklml pipeline
* display envvars on terminal
* Clean up C# cuda tests, and upgrade to Cuda10
* Introduce CUDNN_PATH pipeline varaible
* YAML variable are always uppercased (not true with classic)
* Update C# GPU test to be more meaningful
* remove macos from gpu tests
* remove debugging info for DisableContribOps option
* Remove DisableContrib ops parameters -- use variables only
* Fix typo from = to -
* remove debug steps
* fix typo
* remove unused variable TESTONGPU from some templates
* clean up CUDA env setup scripts
* Remove CUDNN_PATH from setup_env_cuda.bat
* Refactor C# to handle x86
* update run script
* Add Native win x86 tests
* Add native x86 tests for Linux
* Update linux tests scripts to control which tests are run
* update linux image name for x86 to prevent using cached image
* update to not run unit python unit tests unless pybind is specified
* remove --build_wheel as a core common arg. Python cannot run on x86 build
* update OrtGetNumOfDimensions to OrtGetDimensionsCount in rest of C#
* added end-to-end nuget package test
* reset the changes in OnnxRuntime.CSharp.proj
* revert the testdata directory path
* revert inference tests proj file
* added script for running end-to-end tests
* fix in the runtest.bat
* added error checking in runtest
* fixed paths in the test project
* added runtest.sh
* fix protoc path
* updated executable attributes for the runtest scripts
* added some log to debug protoc failures
* removed the protoc and duplicate test code, reuse unit-test code for end-to-end test
* copy always
* fix working dir paths in runtest.sh
* added a build.py flag to download test data without running the c++ tests
* added a script for running the test under docker
* added script for docker run of the test