Cleanup onnx test runner's code

[snnn]

Description

1. Deleted protobuf file onnxruntime/test/proto/tml.proto. It was added by me in 2018. I tried to use it to define a new file format for the test data in onnx and onnx model zoo. Because the existing format didn't support non-tensor types. However, the data format wasn't actually used. And later on we defined another test data format for sparse tensors and the others(You can find the information in testcase.cc). Therefore this PR deletes the outdated code to make thing simpler.
2. Deleted the OnnxModelInfo class in onnx_test_runner.
3. Deleted some outdated tests in onnxruntime/test/ir/onnx_model_test.cc. They now can be covered in ONNX model tests.

To resolve Github issue #23684

Motivation and Context