Key Press should be the first and default behaviour in the dropdown

[peterjc]

Describe the bug

I have tried using ZMK Studio v0.3.1 to define an alterative alphabet layout and the ergonomics of doing this was horrilbe with lots of scrolling. Issue #151 describes one major pain point, this is a related but easier to fix issue.

To Reproduce
Steps to reproduce the behavior:

1. Start ZMK Studio, connect to a keyboard
2. Click on 'Layers +' to start a new layer
3. Give it a name like "HD Promethium" (link)
4. Move the mouse over the layout, note the keys are all "Unknown"
5. Click on the left hand home row index finger key
6. We want to make this &kp H, or "Key Press", "Keyboard H"
7. Look at the bahavour drop down, they are sorted alphabetically and the default is the first entry (logical).
8. Try to find "Key Press", it is somewhere in the middle - prone to misclicks if picking with the mouse

Expected behavior

The behaviour list is dynamic as each keyboard firmware can define its own extras, but "Key Press" should always be listed first and as the default as the single most used option.

Screenshots

Environment (please complete the following information):

• OS: [e.g. iOS] macOS
• Browser or App [e.g. chrome, edge, app] App
• Version [e.g. 22] v0.3.1
• Device [e.g. Corne with nice!nano v2] Gamma Omega TC36K

Additional context

I'm now defining my non-Qwerty layout in code, as I have no wish to repeat the painful experience of this combined with #151. Doing the equivalent in Vial was a lot of point-and-click, but this was worse 😭 - but on the bright side I think making ZMK Studio work mouse-free seems much more realistic than for Vial, a potential win for accessibility.

[peterjc]

Seems this might be fixed with a tweak on top of #75 which does the alphabetical sort to then move keypress to the start as a special case.