[JS/WebGPU] Fix Split and Where to handle corner cases. (#19613)

### Description
<!-- Describe your changes. -->
1. Fix Where operator to handle Boolean input less than 4 bytes.
2. Fix JSEP test harness to use tensor names consistently.


### 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. -->

js/web/lib/wasm/jsep/webgpu/ops/where.ts

@@ -27,7 +27,7 @@ const createWhereOpProgramShader =
           const expressionA = `a_data[index_a${x}][component_a${x}]`;
           const expressionB = `b_data[index_b${x}][component_b${x}]`;
           // eslint-disable-next-line no-bitwise
-          const expressionC = `bool(c_data[index_c${x}] & ${0xff000000 >>> ((3 - x) * 8)}u)`;
+          const expressionC = `bool(c_data[index_c${x}] & (0xffu << (component_c${x} * 8)))`;
           return `
             let output_indices${x} = ${output.offsetToIndices(`global_idx * 4u + ${x}u`)};
             let offset_a${x} = ${a.broadcastedIndicesToOffset(`output_indices${x}`, output)};
@@ -38,6 +38,7 @@ const createWhereOpProgramShader =
             let index_c${x} = offset_c${x} / 4u;
             let component_a${x} = offset_a${x} % 4u;
             let component_b${x} = offset_b${x} % 4u;
+            let component_c${x} = offset_c${x} % 4u;
             ${resStr}[${x}] = ${typeCast}(${expression(expressionA, expressionB, expressionC)});
           `;
         };

js/web/test/data/ops/where.jsonc

@@ -168,5 +168,39 @@
         ]
       }
     ]
+  },
+  {
+    "name": "Where with no attributes",
+    "operator": "Where",
+    "attributes": [],
+    "cases": [
+      {
+        "name": "T[1 1 2 1] T[1 4] T[1 1 2 4] float32 broadcast 1",
+        "inputs": [
+          {
+            "data": [true, false],
+            "dims": [1, 1, 2, 1],
+            "type": "bool"
+          },
+          {
+            "data": [1, 2, 3, 4],
+            "dims": [1, 4],
+            "type": "float32"
+          },
+          {
+            "data": [5, 6, 7, 8, 9, 10, 11, 12],
+            "dims": [1, 1, 2, 4],
+            "type": "float32"
+          }
+        ],
+        "outputs": [
+          {
+            "data": [1, 2, 3, 4, 9, 10, 11, 12],
+            "dims": [1, 1, 2, 4],
+            "type": "float32"
+          }
+        ]
+      }
+    ]
   }
 ]

js/web/test/test-runner.ts

@@ -627,8 +627,8 @@ export async function runModelTestSet(
   try {
     const feeds: Record<string, ort.Tensor> = {};
     const outputsMetaInfo: Record<string, ort.Tensor> = {};
-    testCase.inputs!.forEach((tensor, i) => feeds[context.session.inputNames[i]] = tensor);
-    testCase.outputs!.forEach((tensor, i) => outputsMetaInfo[context.session.outputNames[i]] = tensor);
+    testCase.inputs!.forEach((tensor) => feeds[tensor.name] = tensor);
+    testCase.outputs!.forEach((tensor) => outputsMetaInfo[tensor.name] = tensor);
     const [start, end, outputs] =
         await sessionRun({session: context.session, feeds, outputsMetaInfo, ioBinding: context.ioBinding});
     if (context.perfData.count === 0) {