[FR]: C# formatter

Part of aspect-build/bazel-super-formatter#6 (just starting a new issue specific to C#, so that the discussion can be more focused)

Start with aspect-build/bazel-super-formatter#6, which this issue identifies as the broader discussion, and review how the rules_lint repository runs static analysis tools with Bazel. Define the C# formatter's supported tool and integration scope before identifying the relevant entry points; done means the focused C# formatter request is implemented and verifiable.

Written by the indexing model from the issue text.