lnrpc: move initiator enum out of close summary

Move enum out of CloseSummary struct for more general use. This does
not change the encoding of the enum, and will only cause compile time
errors for existing clients. This enum has not been included in a
release yet, so we can make this move without much disruption.

lnrpc/rpc.proto

@@ -1483,6 +1483,13 @@ message ListChannelsResponse {
     repeated Channel channels = 11;
 }
 
+enum Initiator {
+    INITIATOR_UNKNOWN = 0;
+    INITIATOR_LOCAL = 1;
+    INITIATOR_REMOTE = 2;
+    INITIATOR_BOTH = 3;
+}
+
 message ChannelCloseSummary {
     /// The outpoint (txid:index) of the funding transaction.
     string channel_point = 1;
@@ -1523,13 +1530,6 @@ message ChannelCloseSummary {
     /// Details on how the channel was closed.
     ClosureType close_type = 10;
 
-    enum Initiator {
-        UNKNOWN = 0;
-        LOCAL = 1;
-        REMOTE = 2;
-        BOTH = 3;
-    }
-
     /**
     Open initiator is the party that initiated opening the channel. Note that
     this value may be unknown if the channel was closed before we migrated to

lnrpc/rpc.swagger.json

@@ -1513,16 +1513,6 @@
       ],
       "default": "COOPERATIVE_CLOSE"
     },
-    "ChannelCloseSummaryInitiator": {
-      "type": "string",
-      "enum": [
-        "UNKNOWN",
-        "LOCAL",
-        "REMOTE",
-        "BOTH"
-      ],
-      "default": "UNKNOWN"
-    },
     "ChannelEventUpdateUpdateType": {
       "type": "string",
       "enum": [
@@ -2233,11 +2223,11 @@
           "description": "/ Details on how the channel was closed."
         },
         "open_initiator": {
-          "$ref": "#/definitions/ChannelCloseSummaryInitiator",
+          "$ref": "#/definitions/lnrpcInitiator",
           "description": "*\nOpen initiator is the party that initiated opening the channel. Note that\nthis value may be unknown if the channel was closed before we migrated to\nstore open channel information after close."
         },
         "close_initiator": {
-          "$ref": "#/definitions/ChannelCloseSummaryInitiator",
+          "$ref": "#/definitions/lnrpcInitiator",
           "description": "*\nClose initiator indicates which party initiated the close. This value will\nbe unknown for channels that were cooperatively closed before we started\ntracking cooperative close initiators. Note that this indicates which party\ninitiated a close, and it is possible for both to initiate cooperative or\nforce closes, although only one party's close will be confirmed on chain."
         }
       }
@@ -3183,6 +3173,16 @@
     "lnrpcInitWalletResponse": {
       "type": "object"
     },
+    "lnrpcInitiator": {
+      "type": "string",
+      "enum": [
+        "INITIATOR_UNKNOWN",
+        "INITIATOR_LOCAL",
+        "INITIATOR_REMOTE",
+        "INITIATOR_BOTH"
+      ],
+      "default": "INITIATOR_UNKNOWN"
+    },
     "lnrpcInvoice": {
       "type": "object",
       "properties": {