[DynamicZones] Bulk request dz member statuses on zone boot (#4769)

When dynamic zones are cached on zone boot each dz requests member
statuses from world separately. This causes a lot of network traffic
between world and booted zones when there are a lot of active dzs.

This changes it to make a single request to world on zone boot and a
single bulk reply back.

common/servertalk.h

@@ -196,6 +196,7 @@
 #define ServerOP_DzSaveInvite                 0x0466
 #define ServerOP_DzRequestInvite              0x0467
 #define ServerOP_DzMakeLeader                 0x0468
+#define ServerOP_DzGetBulkMemberStatuses      0x0469
 
 #define ServerOP_LSInfo				0x1000
 #define ServerOP_LSStatus			0x1001
@@ -1555,6 +1556,13 @@ struct ServerDzMemberStatuses_Struct {
 	ServerDzMemberStatusEntry_Struct entries[0];
 };
 
+struct ServerDzCerealData_Struct {
+	uint16_t zone_id;
+	uint16_t inst_id;
+	uint32_t cereal_size;
+	char     cereal_data[1];
+};
+
 struct ServerDzMovePC_Struct {
 	uint32 dz_id;
 	uint16 sender_zone_id;