Misc UI tuning and bugfixing

[samsar]

• Fix bug where if you were on the detailed view and pulled changes, the view would change to the next repo in the list. Now it stays on the same repo, and when you esc out, the repo is still selected
• Fix inconsistent background colours all over the place
• Changed the settings shortcut from c to z, and show it in the shortcuts menu in the main view
• Kept header consistent between main and details views
• Fix the shortcut menu so that it's always centered in all views, even after window resize.
• Move the top row of the header to the top of the screen to make better use of screen space
• Fix CI to ensure tests pass for going to release step