Fixes #8991

Uses OSC 133 esc sequences to keep track of how long commands take to
execute. If the user chooses, commands that take longer than a user
specified limit will trigger a notification. The user can choose between
a bell notification or a desktop notification.

We don't really have any large outstanding regressions on -ng to warrant
keeping this alive anymore. ¡Adiós!

Ghostty has had support for a while (since PR #3124) for parsing progress
reports but never did anything with them. This PR adds the core
infrastructure and an implementation for GTK.

On GTK, the progress bar will show up as a thin bar along the top of
the terminal. Under normal circumstances it will use whatever you have
set as your accent color. If the progam sending the progress report
indicates an error, it will change to a reddish color.

Addresses #7649 for the core and GTK. macOS support will need to be
added later.

This adds an apprt action to show a native GUI warning of some kind when
the child process of a terminal exits.

Also adds a basic GTK implementation of this. In GTK it overlays an
Adwaita banner at the bottom of the window (similar to the banner that
shows up in at the top of windows in debug builds).