Progress Bar support

https://conemu.github.io/en/AnsiEscapeCodes.html#ConEmu_specific_OSC

Some new tools have started using this, but it conflicts with notification support in iTerm2, so iTerm2 users get spammed with notifications instead: https://github.com/charmbracelet/crush/issues/1326

See also the note here: https://ghostty.org/docs/install/release-notes/1-2-0#graphical-progress-bars