Fix: prefix the Nth vehicle with "#" when ungrouped

This is for consistency; most other objects add a # to indicate
it is the Nth of that object, except for Trains / RVs / Ships /
Aircrafts.
This becomes painfully apparent with unnamed vehicles in groups,
which do get a "#".

regression/regression/result.txt

@@ -9075,7 +9075,7 @@ ERROR: IsEnd() is invalid as Begin() is never called
   --Accounting--
     GetCosts():         -5947
     Should be:          -5947
-  GetName():            Road Vehicle 1
+  GetName():            Road Vehicle #1
   SetName():            true
   GetName():            MyVehicleName
   CloneVehicle():       13

src/lang/english.txt

@@ -4732,10 +4732,10 @@ STR_INDUSTRY_NAME_SUGAR_MINE                                    :Sugar Mine
 ##id 0x6000
 STR_SV_EMPTY                                                    :
 STR_SV_UNNAMED                                                  :Unnamed
-STR_SV_TRAIN_NAME                                               :Train {COMMA}
-STR_SV_ROAD_VEHICLE_NAME                                        :Road Vehicle {COMMA}
-STR_SV_SHIP_NAME                                                :Ship {COMMA}
-STR_SV_AIRCRAFT_NAME                                            :Aircraft {COMMA}
+STR_SV_TRAIN_NAME                                               :Train #{COMMA}
+STR_SV_ROAD_VEHICLE_NAME                                        :Road Vehicle #{COMMA}
+STR_SV_SHIP_NAME                                                :Ship #{COMMA}
+STR_SV_AIRCRAFT_NAME                                            :Aircraft #{COMMA}
 
 STR_SV_STNAME                                                   :{STRING1}
 STR_SV_STNAME_NORTH                                             :{STRING1} North