[Proto] Add support for map labels in map proto file

proto/src/main/proto/map.proto

@@ -42,6 +42,7 @@ message ObjectLayer {
   repeated PassageAbility passageMap = 1;
   repeated MapObject objects = 2;
   required string javaImports = 3;
+  repeated MapLabel labels = 4;
 }
 
 enum PassageAbility {
@@ -55,6 +56,12 @@ message MapObject {
   required string code = 3;
 }
 
+message MapLabel {
+  required string label = 1;
+  required uint32 x = 2;
+  required uint32 y = 3;
+}
+
 message ColorLayer {
   required uint32 red = 1;
   required uint32 green = 2;