Don't limit "state" (#2849)

This is apparently some incorrect behaviour that we built as a result of
a spec bug (matrix-org/matrix-spec#1314) where we were applying a filter
to the `"state"` section of the `/sync` response incorrectly. The client
then has no way to know that the state was limited.

This PR removes the state limiting, which probably also helps #2842.

syncapi/routing/context.go

@@ -93,7 +93,6 @@ func Context(
 	}
 
 	stateFilter := gomatrixserverlib.StateFilter{
-		Limit:                   100,
 		NotSenders:              filter.NotSenders,
 		NotTypes:                filter.NotTypes,
 		Senders:                 filter.Senders,

syncapi/routing/search.go

@@ -294,7 +294,7 @@ type SearchRequest struct {
 				BeforeLimit    int  `json:"before_limit,omitempty"`
 				IncludeProfile bool `json:"include_profile,omitempty"`
 			} `json:"event_context"`
-			Filter    gomatrixserverlib.StateFilter `json:"filter"`
+			Filter    gomatrixserverlib.RoomEventFilter `json:"filter"`
 			Groupings struct {
 				GroupBy []struct {
 					Key string `json:"key"`