onnxruntime

Use onnxruntime_fetchcontent_makeavailable cmake function for TRT (#13918)

### Description
Use onnxruntime_fetchcontent_makeavailable cmake function for TRT. See
the comment for the reason.


### Motivation and Context
To support a newer TRT version. Previously they have a "BUILD_EXE" build
option to allow us to exclude such things from build. But in
https://github.com/onnx/onnx-tensorrt/pull/879 they deleted the build
option. It wouldn't be a problem if we continue to use git submodules as
before, because cmake's add_subdirectories function has an
"EXCLUDE_FROM_ALL" keyword. However, cmake's FetchContent module
doesn't. That's why I needed to create our own version of the macro.