drbd: introduce dynamic debug

Incorporate as many out-of-tree changes as possible without changing the
genl API.

Over the years, we restructured this several times, and also changed the
log format.

One breaking change is that DRBD 9 gained "implicit options", like a
connection name. This cannot be replayed here without changing the API,
so save it for later.

Originally-from: Andreas Gruenbacher <agruen@linbit.com>
Originally-from: Philipp Reisner <philipp.reisner@linbit.com>
Originally-from: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20221201110349.1282687-4-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>