Replace publicroomsapi with a combination of clientapi/roomserver/currentstateserver (#1174)

* Use content_value instead of membership

* Fix build

* Replace publicroomsapi with a combination of clientapi/roomserver/currentstateserver

- All public rooms paths are now handled by clientapi
- Requests to (un)publish rooms are sent to the roomserver via `PerformPublish`
  which are stored in a new `published_table.go`
- Requests for public rooms are handled in clientapi by:
    * Fetch all room IDs which are published using `QueryPublishedRooms` on the roomserver.
    * Apply pagination parameters to the slice.
    * Do a `QueryBulkStateContent` request to the currentstateserver to pull out
      required state event *content* (not entire events).
    * Aggregate and return the chunk.

Mostly but not fully implemented (DB queries on currentstateserver are missing)

* Fix pq query

* Make postgres work

* Make sqlite work

* Fix tests

* Unbreak pagination tests

* Linting

currentstateserver/storage/interface.go

@@ -17,6 +17,7 @@ package storage
 import (
 	"context"
 
+	"github.com/matrix-org/dendrite/currentstateserver/storage/tables"
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/gomatrixserverlib"
 )
@@ -31,4 +32,7 @@ type Database interface {
 	GetStateEvent(ctx context.Context, roomID, evType, stateKey string) (*gomatrixserverlib.HeaderedEvent, error)
 	// GetRoomsByMembership returns a list of room IDs matching the provided membership and user ID (as state_key).
 	GetRoomsByMembership(ctx context.Context, userID, membership string) ([]string, error)
+	// GetBulkStateContent returns all state events which match a given room ID and a given state key tuple. Both must be satisfied for a match.
+	// If a tuple has the StateKey of '*' and allowWildcards=true then all state events with the EventType should be returned.
+	GetBulkStateContent(ctx context.Context, roomIDs []string, tuples []gomatrixserverlib.StateKeyTuple, allowWildcards bool) ([]tables.StrippedEvent, error)
 }