FR: allow reverse-debugging

see https://github.com/rr-debugger/rr/wiki/Using-rr-in-an-IDE#cc-extension for an example setup how to launch it with rr, but the main part is to be able to use the reverse-step, reverse-continue, ... options directly from the IDE.
Either enable those by default or configuration.

You can also use GDB itself - see https://sourceware.org/gdb/current/onlinedocs/gdb.html/Process-Record-and-Replay.html, but depending on your machine, gdb version and others, you may only be able to record and then "reverse-step" a view lines - but even that would be nice to be supported with this debug adapter.