Add more advanced SafeArray tests (dotnet/coreclr#21063)

Add more advanced SafeArray tests (dotnet/coreclr#21063)

* Port simple SafeArray tests over from .NET Framework's test suite.

* Clean up native calling conventions.

* Add basic field array -> field SAFEARRAY* tests.

* Fix some hiding stdcall calling convention decorators.

* PR Feedback.

* Rewrite native part of SafeArray tests

* Wrote the managed side of the tests. Non-passing ones are currently commented out.

* Fix up tests and enable marshalling a string[] as a SAFEARRAY of LPSTR or LPWSTR.

* Add blittable records test with a return parameter.

* Add returning non-blittable record safearray test.

* Fix which typedef we're using

* Clean up

* Fix/cleanup RecordNative

* Replace "" with <> for platformdefines.h include.

* Use macro for calling convention.

* PR Feedback.

* Remove residual "Helpers.h" include.

* Fix remaining incorrect calling conventions.

* One more calling convention fix.

Commit migrated from https://github.com/dotnet/coreclr/commit/93d3f4c1f7f8a27c94aad68837dc8dda30c19b02