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).
re-use the auth retry options from the config for initial d.bot.Open and
for registering commands. The latetr is now done with the BulkOverwrite
method, since it seems to work now. For #427.
Webhooks send a POST to an admin-supplied URL when something happens,
with relevant information sent in JSON. One has been added for creating
users in Settings > Webhooks > User Created.
Lazily, the portion of GetUsers which generates a respUser has been
factored out, and is called to send the JSON payload.
A stripped-down common.Req method has been added, which is used by the
barebones WebhookSender struct.
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/.
Harvey Tindall