Add hostfxr_get_dotnet_environment_info API (#48097)

Add hostfxr_get_dotnet_environment_info API (#48097)

* Add hostfxr_get_dotnet_environment_info

* Change access modifiers in structs

* Remove unnecessary context local

* Use global install location if no dotnet_root is specified

* Add framework tests

* Update framework_info comparison

* Remove commented code

* Remove unnecessary marshaling
Export fn

* Add hostfxr_get_dotnet_environment_info to hostfxr exports

* Fail if result is nullptr
Validate size of structs
Test that result_context isn't modified

* Remove version_as_str
Update tests

* Add tests for invalid args