rpcserver+poolrpc: add ListSidecars and CancelSidecar RPCs

With this commit we add two new RPCs for handling sidecar tickets.
ListSidecars will show all sidecar tickets known to the local database,
including those where our node is on the receiving end of a sidecar
channel.
CancelSidecar will cancel a specific sidecar ticket. If an order was
created for it, that bid order will be canceled. Doing so will make sure
the ticket isn't executed any further.

macaroons.go

@@ -142,6 +142,14 @@ var (
 			Entity: "order",
 			Action: "read",
 		}},
+		"/poolrpc.Trader/ListSidecars": {{
+			Entity: "order",
+			Action: "read",
+		}},
+		"/poolrpc.Trader/CancelSidecar": {{
+			Entity: "order",
+			Action: "write",
+		}},
 	}
 
 	// allPermissions is the list of all existing permissions that exist

poolrpc/trader.proto

@@ -186,11 +186,25 @@ service Trader {
     rpc ExpectSidecarChannel (ExpectSidecarChannelRequest)
         returns (ExpectSidecarChannelResponse);
 
-    /* pool: `sidecar decodeticket`
+    /* pool: `sidecar printticket`
     Decodes the base58 encoded sidecar ticket into its individual data fields
     for a more human-readable representation.
     */
     rpc DecodeSidecarTicket (SidecarTicket) returns (DecodedSidecarTicket);
+
+    /* pool: `sidecar list`
+    ListSidecars lists all sidecar tickets currently in the local database. This
+    includes tickets offered by our node as well as tickets that our node is the
+    recipient of. Optionally a ticket ID can be provided to filter the tickets.
+    */
+    rpc ListSidecars (ListSidecarsRequest) returns (ListSidecarsResponse);
+
+    /* pool: `sidecar cancel`
+    CancelSidecar cancels the execution of a specific sidecar ticket. Depending
+    on the state of the sidecar ticket its associated bid order might be
+    canceled as well (if this ticket was offered by our node).
+    */
+    rpc CancelSidecar (CancelSidecarRequest) returns (CancelSidecarResponse);
 }
 
 message InitAccountRequest {
@@ -1232,3 +1246,31 @@ message ExpectSidecarChannelRequest {
 
 message ExpectSidecarChannelResponse {
 }
+
+message ListSidecarsRequest {
+    /*
+    The optional sidecar ID to filter for. If set, the result should either be
+    a single ticket or no ticket in most cases. But because the ID is just 8
+    bytes and is randomly generated, there could be collisions, especially since
+    tickets can also be crafted by a malicious party and given to any node.
+    That's why the offer's public key is also used as an identifying element
+    since that cannot easily be forged without also producing a valid signature.
+    So an attacker cannot overwrite a ticket a node offered by themselves
+    offering a ticket with the same ID and tricking the victim into registering
+    that. Long story sort, there could be multiple tickets with the same ID but
+    different offer public keys, which is why those keys should be checked as
+    well.
+    */
+    bytes sidecar_id = 1;
+}
+
+message ListSidecarsResponse {
+    repeated DecodedSidecarTicket tickets = 1;
+}
+
+message CancelSidecarRequest {
+    bytes sidecar_id = 1;
+}
+
+message CancelSidecarResponse {
+}

poolrpc/trader.swagger.json

@@ -1230,6 +1230,9 @@
     "poolrpcCancelOrderResponse": {
       "type": "object"
     },
+    "poolrpcCancelSidecarResponse": {
+      "type": "object"
+    },
     "poolrpcCloseAccountResponse": {
       "type": "object",
       "properties": {
@@ -1663,6 +1666,17 @@
         }
       }
     },
+    "poolrpcListSidecarsResponse": {
+      "type": "object",
+      "properties": {
+        "tickets": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/poolrpcDecodedSidecarTicket"
+          }
+        }
+      }
+    },
     "poolrpcLsatToken": {
       "type": "object",
       "properties": {