Add `local_current_membership` table (#6655)

Currently we rely on `current_state_events` to figure out what rooms a
user was in and their last membership event in there. However, if the
server leaves the room then the table may be cleaned up and that
information is lost. So lets add a table that separately holds that
information.

1 files changed, 1 insertions, 0 deletions

diff --git a/changelog.d/6655.misc b/changelog.d/6655.misc
new file mode 100644
index 0000000000..01e78bc84e
--- /dev/null
+++ b/changelog.d/6655.misc
@@ -0,0 +1 @@
+Add `local_current_membership` table for tracking local user membership state in rooms.