lnrpc+lnd: adds required reserve in walletbalance rpc

lnrpc/lightning.proto

@@ -2567,6 +2567,9 @@ message WalletBalanceResponse {
     // other usage.
     int64 locked_balance = 5;
 
+    // The amount of reserve required.
+    int64 reserved_balance_anchor_chan = 6;
+
     // A mapping of each wallet account's name to its balance.
     map<string, WalletAccountBalance> account_balance = 4;
 }

lnrpc/lightning.swagger.json

@@ -6646,6 +6646,11 @@
           "format": "int64",
           "description": "The total amount of wallet UTXOs held in outputs that are locked for\nother usage."
         },
+        "reserved_balance_anchor_chan": {
+          "type": "string",
+          "format": "int64",
+          "description": "The amount of reserve required."
+        },
         "account_balance": {
           "type": "object",
           "additionalProperties": {