syncapi: add more tests; fix more bugs (#2338)

* syncapi: add more tests; fix more bugs

bugfixes:
 - The postgres impl of TopologyTable.SelectEventIDsInRange did not use the provided txn
 - The postgres impl of EventsTable.SelectEvents did not preserve the ordering of the input event IDs in the output events slice
 - The sqlite impl of EventsTable.SelectEvents did not use a bulk `IN ($1)` query.

Added tests:
 - `TestGetEventsInRangeWithTopologyToken`
 - `TestOutputRoomEventsTable`
 - `TestTopologyTable`

* -p 1 for now

test/db.go

@@ -121,6 +121,7 @@ func WithAllDatabases(t *testing.T, testFn func(t *testing.T, db DBType)) {
 	for dbName, dbType := range dbs {
 		dbt := dbType
 		t.Run(dbName, func(tt *testing.T) {
+			tt.Parallel()
 			testFn(tt, dbt)
 		})
 	}