replace AddContactMethods with a more generalised SetContactMethods,
which can set (or leave alone) contact method addresses/names/ids and
set (or leave alone) contact preferences. A little awkward to use, but
works everywhere, and now a bunch of Jellyseerr integration features are
present for Ombi (which they should've been anyway).
Added a new common.ConfigurableTransport interface which mediabrowser,
ombi, jellyseer, discord, telegram and matrix (i.e.
ThirdPartService/ContactMethodLinker) now all implement. proxies are
bound to them in main.go, Email is still a special case (but from the
previous commit, mailgun does use the proxy).
mautrix/go has been updated, and context.TODO()s stuck everywhere since
I still don't really comprehend why I should use them (FIXME literally).
jellyseerr already did this, but it's been standardised a little more.
Mediabrowser uses it's own genericErr function and error types due to
being a separate package, while jellyseerr and ombi now share errors
defined in common/.
NOTE: If you previously used the Ombi integration, New ombi users
won't be created until you set this up.
Ombi settings can be added to a profile in Settings > User Profiles.
The "Modify settings" options will now apply to ombi if the selected
profile has ombi settings.
