[NativeAOT] Review COOP helpers that may cause long GC suspension pauses.

[VSadov]

RhpCopyObjectContents can cause long pauses when copying large arrays.
it was observed on System.Security.Cryptography.Tests.

Other COOP_PINVOKE_HELPER need to be examined as well on whether the potential wait is bounded and short.
For example RhCompareObjectContentsAndPadding might have the same issues.

In the copy object/array case, we can use the same approach as in CoreClr that does the copying in managed code and if needs to set cards, does it in chunks. Perhaps the code can be unified?

RhBulkMoveWithWriteBarrier has the same issue. Long pauses were observed when running System.Private.Uri.Functional.Tests

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[VSadov]

This might be ok to do in v.Next