Dropdown for selecting Docs: Feat: Chore: Etc.

### Is your feature request related to a problem? Please describe.
I follow a very strict pattern in my commit messages, which usually looks like:
`docs: add mention of breaking issue in uploading new files`
`chore: initial rebrand to gmdp`
`bugfix: fix crash when installing unregistered plugin`
`feat: add button to close window`

Sometimes, a project can use really long message prefixes. One of my projects has the prefix:
```
gitfix/squash:
```
as a legacy type I created a long time ago. Typing all of that every time is a pain.

### Describe the solution you'd like
It would be neat if lazygit could have selectable dropdown of prefixes that can be configured in some way, either via a config in the project itself, or as something in `.git`

### Describe alternatives you've considered
Copypasting prefixes, but that can be quite the mess if there are many conflicting prefixes.
Keeping prefixes in the project folder in a text file then getting it from there

### Additional context
Add any other context or screenshots about the feature request here.

Already put one screengrab