Terminal layout: another approach
This MR reverts !345 (merged) due to accessibility concerns (#213 (closed)) and tries to improve the old terminal layout by adding a new row of small buttons with modifiers and arrows.
The intention would be to actually take additional space with the new row (and make it a bit higher too), but since it's not currently possible in Squeekboard it has to shrink the rest of the rows a bit.
/cc @codingellie @btantau @dorota.czaplejewicz @tobias.bernard