Problem:
- Various `TermRequest` handlers which all do similar things.
- `tty.query` is specific to `XTGETTCAP DCS`, can't be reused for other kinds of terminal queries.
Solution:
Provide `tty.request()`.
Problem:
Similar to clearmatches(), it's always necessary to provide a fallback
that allows the user to do a "global reset" when something goes wrong.
Solution:
vim.img.del(math.huge) clears all images.
Use kitty's d=A command to clear all placements in a single
escape sequence rather than N individual deletes, also freeing stored
image data not referenced by the scrollback buffer.
