[Lens] Visual bugs with accordions for inline editor

[ ] There are currently some issues present in the flyout when the user has greatly increased the height of the ES|QL editor and/or they have reduced the height of their browser's viewport:
- There are overflow issues present with the accordion arrows (see screenshot below).
- Additionally, open accordions may also be rendered so short in height that they would be unusable in some extreme scenarios. Should we attempt to prevent open accordions from getting that small (via a min-height or some other method)? Also, for the sake of responsiveness, at very small viewport heights, should we remove the accordions' existing inner content scrolling styles (allowing them to grow as tall as the height of their contents) and move the scrolling styles to a parent element of the accordions? This one may be a can of worms, so feel free to split off as a separate PR if you wish.

elastic / kibana