Improve distinction between pushed and unpushed commits

### Is your feature request related to a problem? Please describe.
In the commit history pane, the green/yellow/red coloration doesn't provide a clear distinction between pushed vs. unpushed commits until after a branch has been pushed for the first time. Yellow is ambiguous. This makes it harder to determine whether I need to push and the commits for which I can safely rewrite history.

Functionally, I'd like to have distinct indications for "on main [Y/N]" and "pushed to remote [Y/N]."

### Describe the solution you'd like
I don't have a particular preference but I can think of some options:
- Regular vs. bright colors: this might be too subtle and some themes use the same color for both variants.
- Regular vs. bold/italic text: Support for bold/italic depends on the terminal. It would be nice to have as an option, though.
- Separate colors for the glyph used to represent a commit and the commit SHA.
- Add a delimiter (e.g. horizontal line) between the pushed and unpushed commits on the branch.
- Add a glyph indicating the location of the remote HEAD.
- Make unpushed (red) a higher priority than not on main (yellow).

### Describe alternatives you've considered
None

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