Added BoardIdentify gRPC call

Author: cmaglie

rpc/cc/arduino/cli/commands/v1/board.pb.go

@@ -237,3 +237,15 @@ message BoardSearchResponse {
   // List of installed and installable boards.
   repeated BoardListItem boards = 1;
 }
+
+message BoardIdentifyRequest {
+  // Arduino Core Service instance from the `Init` response.
+  Instance instance = 1;
+  // A set of properties to search (can be taken from a Port message).
+  map<string, string> properties = 2;
+}
+
+message BoardIdentifyResponse {
+  // List of matching boards (they may have an FQBN with options set).
+  repeated BoardListItem boards = 1;
+}