Analyzers should live in the Roslyn repo

With RequiresAssemblyFiles and RequiresDynamicCode analyzers we are deviating from the common practice of building generic .NET libraries analyzers in https://github.com/dotnet/roslyn-analyzers. Moving these analyzers to that repo would help with

- Making issue reporting simple (all analyzers error are reported at single well know place).
- Get visibility to .net analyzers community and open it to much larger community.
- Make versioning/preview work consistently, e.g. people are used to enable netXYZ analyzers with NetAnalyzers feed
- RequiresDynamicCodeAttribute is not linker or even NativeAOT specific analyzer and only depends on libraries API surface

On the other hand, analyzers share a lot of implementation and test code that currently is in the linker repository, so we need to be sure that
- We are able to share the code
- We are able to verify correctness via the linker tests
- We can ensure equivalence between the linker and the analyzer