Remove the action buttons in commit details view

[phil294]

As hinted in #86, these blue buttons take up just SO much space:

I'd like to remove them, as everything is accessible via right click context menu too. Perhaps add small ellipsis (...) menus instead for folks without right click / for a11y purposes.

Right clicking on a branch name in the right details bar should also be made possible, currently it only works in the main view.

There's a config setting for this already, but I'd just switch the default value. If someone has a different opinion, now's the time.

[hansu]

I am fine whether you disable they by default or remove them completely.
As far as I understood, single buttons can still be the added.
(Just for completeness, the setting is "git-log--graph.hide-sidebar-buttons": true)

[J-Sorenson]

The buttons need to be there by default because they have the hover help for new users. Familiar users can apply "hide-sidebar-buttons" once they are familiar with them. That said, I wish that setting only removed the buttons and kept the branch names in the sidebar. We have long branch titles, and commits with multiple branches means we can't access some branches from the main view. Gitk lists the branches in the commit details, so I would like GitLG to do the same.