If you want a specific one, you can always overwrite it, but a dive site
with a uuid of 0 breaks some of our assumptions.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Sometimes we want to create a dive site just based on a name, sometimes we
have both a name and GPS coordinates. Let's make a helper for either case.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>