Assign ID for poolDenom (#456)

Create dedicated PoolMetadata storage 
Add associated lookups and refs

---------

Co-authored-by: Julian Compagni Portis <julian@terrascope.io>

proto/duality/dex/genesis.proto

@@ -1,22 +1,26 @@
 syntax = "proto3";
+
 package duality.dex;
 
 import "gogoproto/gogo.proto";
 import "duality/dex/params.proto";
 import "duality/dex/limit_order_tranche_user.proto";
 import "duality/dex/limit_order_tranche.proto";
 import "duality/dex/tick_liquidity.proto";
+import "duality/dex/pool_metadata.proto";
+
 // this line is used by starport scaffolding # genesis/proto/import
 
 option go_package = "github.com/duality-labs/duality/x/dex/types";
 
 // GenesisState defines the dex module's genesis state.
 message GenesisState {
-  Params params = 1 [(gogoproto.nullable) = false];
-  repeated TickLiquidity tickLiquidityList = 2 [(gogoproto.nullable) = true];
-  repeated LimitOrderTranche inactiveLimitOrderTrancheList = 6 [(gogoproto.nullable) = true];
-  repeated LimitOrderTrancheUser limitOrderTrancheUserList = 7 [(gogoproto.nullable) = true];
-
-
+           Params                params                        = 1 [(gogoproto.nullable) = false];
+  repeated TickLiquidity         tickLiquidityList             = 2 [(gogoproto.nullable) = true ];
+  repeated LimitOrderTranche     inactiveLimitOrderTrancheList = 3 [(gogoproto.nullable) = true ];
+  repeated LimitOrderTrancheUser limitOrderTrancheUserList     = 4 [(gogoproto.nullable) = true ];
+  repeated PoolMetadata poolMetadataList  = 5 [(gogoproto.nullable) = false];
+           uint64       poolCount = 6;
   // this line is used by starport scaffolding # genesis/proto/state
 }
+

proto/duality/dex/pool.proto

@@ -5,7 +5,10 @@ option go_package = "github.com/duality-labs/duality/x/dex/types";
 import "gogoproto/gogo.proto";
 import "duality/dex/pool_reserves.proto";
 
+// NOTE: This struct is never actually stored in the KV store. It is merely a convenience wrapper for holding both sides of a pool.
+
 message Pool {
-    PoolReserves lower_tick0 = 1;
-    PoolReserves upper_tick1 = 2;
-}
+    uint64 ID = 1;
+    PoolReserves lower_tick0 = 2;
+    PoolReserves upper_tick1 = 3;
+}

proto/duality/dex/pool_metadata.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+package duality.dex;
+
+option go_package = "github.com/duality-labs/duality/x/dex/types";
+
+import "duality/dex/pair_id.proto";
+
+message PoolMetadata {
+  uint64 ID = 1;
+  int64 tick = 2;
+  uint64 fee = 3;
+  PairID pairID = 4;
+}