Add instrumentation for RewriteHistory Gitaly RPC (remove blobs)

What does this MR do and why?

Adds instrumentation for the RewriteHistory Gitaly RPC (remove blobs) feature

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

How to set up and validate locally

1. Enable the rewrite_history_ui feature flag.
2. Navigate to Project > Setting > Repository > Repository maintenance
3. Click on Remove blobs
4. The remove blobs drawer should open
5. Add more than 40 characters to the textarea
6. Confirm the removal
7. The click_remove_blob_button_repository_settings event should be published

Related to #461887