[lldb] Support OSC escape codes for native progress (#162162)
This PR adds support for emitting the OSC `9;4` sequences to show a GUI
native progress bar.
There's a limited number of terminal emulators that support this, so for
now this requires explicit opt-in through a setting. I'm reusing the
existing `show-progress` setting, which became a NOOP with the
introduction of the statusline. The option now defaults to off.
Implements #160369