Fix error message for invalid assembly name

[jkotas]

The error message is always used for invalid assembly name. Delete mention of codebase to avoid confusion.

[dotnet-issue-labeler]

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

[danmoseley]

there's a number of strings in mscorrc.rc and mscorurt.rc that relate to the GAC or AppDomains. Yet (per my recent change) are at least referenced in the code. Should we clean those up too?

[jkotas]

there's a number of strings in mscorrc.rc and mscorurt.rc that relate to the GAC or AppDomains.

The HRESULTs associated with these error messages are never going to be produced by CoreCLR.

The only reason for these error messages to exist is that the interop APIs recognize them when mapping HRESULTs to exceptions and error messages. For example, this is going to print error message that talks about GAC:

Console.WriteLine(System.Runtime.InteropServices.Marshal.GetExceptionForHR(unchecked((int)0x80131050), new IntPtr(-1)));

It would be an observable behavior change to stop recognizing these HRESULTs. I think it would be ok to clean this up if you are interested doing it.