Collect room-version variations into one place (#4969)

Collect all the things that make room-versions different to one another into
one place, so that it's easier to define new room versions.

synapse/api/constants.py

@@ -102,46 +102,6 @@ class ThirdPartyEntityKind(object):
     LOCATION = "location"
 
 
-class RoomVersions(object):
-    V1 = "1"
-    V2 = "2"
-    V3 = "3"
-    STATE_V2_TEST = "state-v2-test"
-
-
-class RoomDisposition(object):
-    STABLE = "stable"
-    UNSTABLE = "unstable"
-
-
-# the version we will give rooms which are created on this server
-DEFAULT_ROOM_VERSION = RoomVersions.V1
-
-# vdh-test-version is a placeholder to get room versioning support working and tested
-# until we have a working v2.
-KNOWN_ROOM_VERSIONS = {
-    RoomVersions.V1,
-    RoomVersions.V2,
-    RoomVersions.V3,
-    RoomVersions.STATE_V2_TEST,
-    RoomVersions.V3,
-}
-
-
-class EventFormatVersions(object):
-    """This is an internal enum for tracking the version of the event format,
-    independently from the room version.
-    """
-    V1 = 1
-    V2 = 2
-
-
-KNOWN_EVENT_FORMAT_VERSIONS = {
-    EventFormatVersions.V1,
-    EventFormatVersions.V2,
-}
-
-
 ServerNoticeMsgType = "m.server_notice"
 ServerNoticeLimitReached = "m.server_notice.usage_limit_reached"