rpc: break down wallet balance by accounts

lnrpc/rpc.proto

@@ -2254,8 +2254,17 @@ message ChannelEventUpdate {
     UpdateType type = 5;
 }
 
+message WalletAccountBalance {
+    // The confirmed balance of the account (with >= 1 confirmations).
+    int64 confirmed_balance = 1;
+
+    // The unconfirmed balance of the account (with 0 confirmations).
+    int64 unconfirmed_balance = 2;
+}
+
 message WalletBalanceRequest {
 }
+
 message WalletBalanceResponse {
     // The balance of the wallet
     int64 total_balance = 1;
@@ -2265,6 +2274,9 @@ message WalletBalanceResponse {
 
     // The unconfirmed balance of a wallet(with 0 confirmations)
     int64 unconfirmed_balance = 3;
+
+    // A mapping of each wallet account's name to its balance.
+    map<string, WalletAccountBalance> account_balance = 4;
 }
 
 message Amount {

lnrpc/rpc.swagger.json

@@ -5770,6 +5770,21 @@
         }
       }
     },
+    "lnrpcWalletAccountBalance": {
+      "type": "object",
+      "properties": {
+        "confirmed_balance": {
+          "type": "string",
+          "format": "int64",
+          "description": "The confirmed balance of the account (with \u003e= 1 confirmations)."
+        },
+        "unconfirmed_balance": {
+          "type": "string",
+          "format": "int64",
+          "description": "The unconfirmed balance of the account (with 0 confirmations)."
+        }
+      }
+    },
     "lnrpcWalletBalanceResponse": {
       "type": "object",
       "properties": {
@@ -5787,6 +5802,13 @@
           "type": "string",
           "format": "int64",
           "title": "The unconfirmed balance of a wallet(with 0 confirmations)"
+        },
+        "account_balance": {
+          "type": "object",
+          "additionalProperties": {
+            "$ref": "#/definitions/lnrpcWalletAccountBalance"
+          },
+          "description": "A mapping of each wallet account's name to its balance."
         }
       }
     },