[FEAT] Enter to select first result in app launcher

[atyrode]

When using the rofi-like app launcher, if I type "fire" for Firefox for instance, and it appears as the first result, pressing the Enter key will not select the first result and instead open the Explorer on Windows.

It would be ideal to be able to press Enter to open the first result, mimicking the behavior of the Spotlight feature on MacOS. It could also work as an option.

An alternative would be the arrow keys, but it's less convenient and requires an extra movement.

This request stems specifically from the fact that on my setup, this happens when searching:

And it makes pressing Tab (and Enter anyway) tedious as it sometimes means a double press.

[eythaann]

The app launcher needs some polish, yep.