Class Throttler implements the bruteforce protection for security actions in
Nextcloud.
It is working by logging invalid login attempts to the database and slowing
down all login attempts from the same subnet. The max delay is 30 seconds and
the starting delay are 200 milliseconds. (after the first failed login)
As discussed we move all old style classes (OC_FOO_BAR) to legacy.
Then from there we can evaluate the need to convert them back or if they
can be fully deprecated/deleted.