bug: vehicle-setup: servo function limits cover slider handles

[ES-Alexander]

Current behaviour

Clicking on a servo function brings up a dialog that allows setting the min/max/trim, but the displayed value annotations overlap the circle handles, which seems unpolished:

Desired solution

Move them up, and ideally change them to more of a callout design, with a little triangle pointing from the annotation background to the circle:

 __________
|____  ____|
     \/
     O