[NativeAOT] Fail if a ILCompiler package runtime major version is different from target runtime

[LakshanF]

We support letting the user add an explicit ILCompiler package reference without specifying PublishAOT property (see test scenario here). This is as part of the user story for native AOT scenarios.

But we should generate an error when the targeted runtime major version is different from the package version as indicated in this issue comment.

[jkotas]

The same problem can occur even when targeting the same major version, especially when updating between preview versions.

I think we should produce a warning when somebody specifies an explicit ILCompiler package reference. The explicit ILCompiler package references should be only used when one needs to validate a bug fix or similar situations.