Support for rebase/amends using `git revise` for much faster performance

**Is your feature request related to a problem? Please describe.**
Having started to use https://github.com/mystor/git-revise/ for rebases and amends, I'm now frustrated by the slow performance of git rebase inside LazyGit. I've been able to create custom commands for amend operations, but rebase is harder to do, since that would mean losing the built-in UI operations.

**Describe the solution you'd like**
It would be great to be able to customize the command that gets called in place of `git rebase`. The default would be `git rebase`, but one could change it to use `git revise`, since the syntax seems very close (one could even direct it to a wrapper script that translates the arguments if needed).

**Describe alternatives you've considered**
I've considered using custom commands to replace the `r` key, but this would mean forgoing the UI that already exists for rebase operations.

**Additional context**
On large repos, rebase operations can easily take 10 seconds or more. With git revise, they are almost immediate, meaning less loss of focus for the developer.