This implements #246 and also should improve #561 a bit.

The window height is dynamic but with a max based on the window height now. Previously there was a fixed max height.
To prevent the window from being placed inconsistently or move up and down when you type I had to move it up a bit more.

The maximum amount of items result view will now be either the amount of characters in the jump code setting (default: 36) or 25 if the jump codes have been disabled. This can be changed. I just went with something. This is also applied for extensions results, not just the search results and the file browser results like before. So extension devs no longer should have to deal with this.

I think the "Number of frequent apps to show" setting makes less sense now. I would rather have a resize feature (drag corners) that sets the max height and with and remembers them, let that be the determining factor and change bck the option to a checkbox if they want to show frequent apps or not.

The theme css hides the actual scrollbar, but you can scroll with the scroll wheel and you can press up and down arrows and tab to go to the next result, which will scroll.

Checklist

• Verify that the test command ./ul test is passing (the CI server will check this if you don't)
• Update the documentation according to your changes (when applicable)
• Write unit tests for your changes (when applicable)