Reorganize menu items

[fcollonval]

The "Git" menu is in need of a reorg (we definitely don't need a menu item that clicks the sidebar button for the user, and a menu item that opens a new terminal and cd's to the current dir is too general. It should maybe be in the main jlab "File" menu, tho). That's yet another separate issue though.

Originally posted by @telamonian in #448 (comment)

[telamonian]

I vote that we prune the:

• "Git Interface"
• "Git Command in Terminal"

menu items for the reasons stated in the first post above.

If not pruned, at the least the "Init" item needs to be greyed out when the user is currently in a valid repo.

As to what actions should be in the Git menu, here's one possible minimal list:

• Init
• Push
• Pull
• Rebase

These are all actions that are commonly seen in the VCS menus of various IDEs. If anyone has strong feelings one way or another about what should get included in the "Git" menu, please comment below. Otherwise, I'll get around to a PR with the above proposal.

[fcollonval]

I agree on the proposed changes. But I would keep the open terminal in current repo feature at some other place.

We could add it at the top of the sidebar with the push and pull buttons and have the repository path below like for the filebrowser.

Note: I'll try to find time to add a feature for pinning the repo path.

[fcollonval]

It may be interesting to add :

• Clone