[Clang-Tidy] Preserve Message, FileOffset, FilePath in Clang-Tidy YAML output

Summary:
To get properly integration Clang-Tidy with CLion IDE, next things were implemented:
* Preserve `Message`, `FileOffset`, `FilePath` in the clang-tidy output.
* Export all diagnostics, not just the ones with fixes
* Test-cases

Reviewers: alexfh, ilya-biryukov

Subscribers: mgorny, JDevlieghere, xazax.hun, cfe-commits

Tags: #clang-tools-extra

Patch by Vladimir Plyashkun!

Differential Revision: https://reviews.llvm.org/D35349

llvm-svn: 308015