[clang-tools-extra] [clang-tidy] Update google todo checker with style guide changes. (PR #165565)

[Quentin Khan via cfe-commits]

qukhan wrote:

> Please add release notes.

Done.

> Could we make option in what style should fixes work? [...]
> To keep codebases consistent, we should provide a way to choose fixes style.

Done. I added the `google-readability-todo.Style` option, which accepts the values `Parentheses` and `Hyphen` for the previous and current style.

> I didn't find in google docs that `TODO(...)` is considered deprecated

Unfortunately I haven't found any other publicly available information about that. The formats in the [style guide] are in order of preference.

[style guide]:https://google.github.io/styleguide/cppguide.html#TODO_Comments




https://github.com/llvm/llvm-project/pull/165565