This makes quickrun, *doom eval* and *Pp Eval Output* buffers behave
better.
Eval output buffers should a) shrink themselves to the size of their
output (within reason), b) *not* grab focus, and c) be easy to close
from afar with C-g/Escape.
Gotchas:
1. Quickrun gets output asynchronously, so we shrink it on
quickrun-after-run-hook, not in the popup rule.
2. *doom eval* and *Pp Eval Output* opens with its output ready, so the
popup system may shrink those to fit.
3. *doom eval* and *Pp Eval Output* handle window selection themselves.
Let them by setting the select window parameter to #'ignore.
d443aed25c