Add methods for emitting diagnostics with no location as well as a special diagnostic for configuration errors.
These show up in the errors as [clang-tidy-config].
The reason to use a custom name rather than the check name is to distinguish the error isn't the same category as the check that reported it.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D91885
Summary: Change all checks that take enums as configuration to use enum specific methods in `ClangTidyCheck::OptionsView`.
Reviewers: aaron.ballman, alexfh
Reviewed By: aaron.ballman
Subscribers: wuzish, nemanjai, kbarton, arphaman, xazax.hun, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D76606