[clang-tidy] Added support for validating configuration options
Summary:
Adds support for `ClangTidyCheck::OptionsView` to deteremine:
- If an option is found in the configuration.
- If an integer option read from configuration is parsable to an integer.
- Parse and Serialize enum configuration options directly using a mapping from `llvm::StringRef` to `EnumType`.
- If an integer or enum option isn't parseable but there is a default value it will issue a warning to stderr that the config value hasn't been used.
- If an enum option isn't parsable it can provide a hint if the value was a typo.
Reviewers: aaron.ballman, alexfh, gribozavr2
Reviewed By: aaron.ballman
Subscribers: xazax.hun, cfe-commits
Tags: #clang, #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D77085