Redraw only the spinner when nothing else has changed

[AntoineGS]

PR Description

This fixes #4734, where lazygit would use a lot of CPU when the spinner was shown due to redrawing the entire screen every time the spinner needed a redraw.
The change adds the ability to request a UI redraw without invalidating the full UI, thus only redrawing the spinner, re-routing the spinner to this new flow.
CPU usage on a chromebook went from 60% to 5% when the spinner is shown.

Changing the refresh rate of the spinner from 50ms to 200ms brings it down from 5% to 1% if ever we would like to change the default, personally I prefer the slower moving spinner, but that's subjective.

Please check if the PR fulfills these requirements

• Cheatsheets are up-to-date (run go generate ./...)
• Code has been formatted (see here)
• Tests have been added/updated (see here for the integration test guide)
• Text is internationalised (see here)
• If a new UserConfig entry was added, make sure it can be hot-reloaded (see here)
• Docs have been updated if necessary
• You've read through your own file changes for silly mistakes etc

[AntoineGS]

Went in a rabbit hole so it'll take some time to wrap up a working solution, my original approach introduced a bug where the full redraw event could be lost while the spinner was shown. I'll let you know when I am done!

[AntoineGS]

Alright so the problem was that some processes that update the layout do not themselves request a redraw and assumed it would be done through the ticker loop, adding a single full redraw after the ticker has completed (aka whatever job it was doing is done) fixed my issue.
Ready for review :)