Redesign access to recent comparisons

I would love having a list of recent comparisons displayed when opening a new tab. Kinda like what GNOME Builder does when it works. Gitg does it too (and always works).

The "new tab" would have the current 3 big buttons + that list:

• if i click on an item of the list, it opens the comparison in the same tab
• if i click on a big button to start an actually new comparison, it hides the list and show the file selectors/checkbuttons/other options

Using such a gtklistbox would allow the app to display richer informations than the current "simple" menu, for example the full path of the compared directories/files could be written in smaller character just under the names of the directories/files