Icon Renaming: git icons

I would like to propose a renaming of the `git` icons. These icons can be used in conjunction with any version control system. What about renaming them into `code-branch`, `code-commit`, `code-pull-request` etc.?

The issue identifies the git icon names but no files or tests. Start by locating the existing git icon definitions and all references to their names, then review the five-comment discussion for the intended naming scheme. Done means the agreed names are applied consistently without breaking icon usage.

Written by the indexing model from the issue text.