added support for cmake "find_package" (#8919)
**Description**:
Adds support for cmake find_package.
**Motivation and Context**
As mentioned in issue #7150 onnxruntime doesn't have support for CMake
find_package, this PR adds that and also adds the CMake package version
file. Now anyone can link onnxruntime like this:
```cmake
find_package(onnxruntime)
add_executable(test Source.cpp)
target_link_libraries(test PRIVATE onnxruntime::onnxruntime)
```
this also simplifies #3124
