Show loading indicator during git merge --continue

### Is your feature request related to a problem? Please describe.
The `git merge --continue` handler when finishing resolving a merge conflict has no loading indicator. We're using pretty extensive git hooks including a precommit hook that can run for quite some time when staging dozens of files (which happens in a master merge).

### Describe the solution you'd like
Some kind of loading indicator / console output would be enough. Right now I press `Enter` when the popup 'All changes resolved. Do you wish to continue the merge?' appears and **nothing** visible happens. Always looks like lazygit crashed.
The same is true to a lesser extent with commits in general, but at least in this case there is something happening in the bottom left corner.