Srv and msg for listing maps (#8)

Co-authored-by: Dhruv Tyagi <dhruv@polymathrobotics.com>

Author: dhruvtya

CMakeLists.txt

@@ -45,6 +45,7 @@ rosidl_generate_interfaces(${PROJECT_NAME}
   "msg/Route.msg"
   "msg/HttpRequest.msg"
   "msg/HttpResponse.msg"
+  "msg/MapIdNamePair.msg"
   "srv/FetchRouteNode.srv"
   "srv/ModifyRouteNode.srv"
   "srv/ModifyRouteEdge.srv"
@@ -60,6 +61,7 @@ rosidl_generate_interfaces(${PROJECT_NAME}
   "srv/StopBagRecording.srv"
   "srv/GetBagRecordingStatus.srv"
   "srv/ListBagRecordings.srv"
+  "srv/ListMaps.srv"
   "action/GenerateOfflineMap.action"
   DEPENDENCIES ${dependencies}
 )

msg/MapIdNamePair.msg

@@ -0,0 +1,3 @@
+# Pair of map ID and name
+uint16 map_id
+string map_name

srv/ListMaps.srv

@@ -0,0 +1,13 @@
+## Request
+
+---
+## Response
+
+# Indicate successful run of service
+bool success
+
+# List of maps
+MapIdNamePair[] maps_list
+
+# Error messages
+string error