Description of the new feature/enhancement

These are the counterparts of OSC 4, 10, 11 to reset the default color. (And continue the line with 117, 119 if 17, 19 get implemented, etc.)

Proposed technical implementation details (optional)

In VTE + GNOME Terminal we figured out the best is if the OSC 4, 10, 11 sequences have precedence over the UI / config file settings. That is, for each color slot, if its value is defined via OSC 4, 10, 11 then that one is used and the one in the settings is ignored. If a value hasn't been defined via OSC 4, 10, 11, or has been reset via OSC 104, 110, 111 then the value specified in the terminal emulator's settings is used. This way re-applying the same settings is an idempotent operation. (Previously the two sources were fighting with each other, both overwriting the value in the same slot. That way re-applying the user config (e.g. "altering" a color to the same value) would invalidate a previous OSC, which was bad.)