This is quite a big update, the new feature is that when the
program starts it loads the next update time from the db if
present. If so it resumes the timers from there. Maximum wait
time is currently capped at 24h.
TimerOroApi is not templated on methods anymore, rather on
the new DBOperation enum. This is so that it has that enum
value to pass it to other functions. This could've been a
separate commit, but wth...
Magic enum allows me to iterate over an enum's values at
build time, it's useful for building the query in OriginsDB
for the SELECT in the access table
(see make_select_last_access_str()).
