Right now, if certain users should be excluded, that would have
to be part of the user-locators already. This is annoying because
it's hard to write "generic" user locators when you want to exclude
just a couple of people in certain cases.
In Flow, for example, we have user-locators for users watching a
board or topic. We don't want to send the notification to people
that have also been mentioned in that post (they'll get a separate
notification). We could build that exception into those
user-locators, but then we couldn't re-use them in other places...
This basically means we couldn't use EchoUserLocator::locateUsersWatchingTitle,
we would have to roll our own that also excludes mentioned users.
Instead, this lets you add 'user-filters' (that functionality
actually exists already, but is not currently exposed), which
lists users to not send the notification to, even though they could
be in a user-locator.
Bug: T125428
Change-Id: Ifa0e2d3283f57624af4c5ec264f9f66223508e83
* Moved most of the content from notify to getEventNotifyTypes
* Added phpunit test verifying per-event config overrides defaults
* Remove special-snowflake welcome handling with proper configuration
Change-Id: Ic1aae11d37f23f2b7b8abe3c1edaa414e29be021
