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).
Currently uses an API key (Seems simpler for the user than importing the
jfa-go user and granting perms). Strategy as follows:
* MustGetUser(jfID) function checks the cache for user, if not, calls
Jellyseerr's importer passing jfID. From either, the user object is
returned, which (in later commits) can be used to update the user's
email (and potentially other info).
My API key is in there rn but its for a local testing instance, who
cares.
