Add new function: GetMapDisplayName.

This function will resolve the name of a map using FindMap, then (if applicable), will turn a workshop map name into a nicely formatted name.

Currently only TF2 and CS:GO Map Workshops are supported.  More can be added at a later date.

This function returns false if a map was not found, but true in any other instance even if FindMap could not resolve the map name.

This patch also updates the following core plugins to use this GetMapDisplayName:

BaseTriggers
BaseVotes
MapChooser
NextMap
Nominations
RandomCycle
RockTheVote

plugins/include/halflife.inc

@@ -167,6 +167,24 @@ native bool:IsMapValid(const String:map[]);
  */
 native FindMapResult FindMap(const char[] map, char[] foundmap, int maxlen);
 
+/**
+ * Get the display name of a workshop map.
+ * 
+ * Note: You do not need to call FindMap first.  This native will call FindMap internally.
+ * 
+ * @param map 			Map name (usually same as map path relative to maps/ dir,
+ *						excluding .bsp extension).
+ * @param displayName	Map's display name, i.e. cp_mymapname or de_mymapname.
+ *						If FindMap returns FindMap_PossiblyAvailable or FindMap_NotFound,
+ *						the map cannot be resolved and this native will return false,
+ *						but displayName will be a copy of map.
+ * @param maxlen		Maximum length to write to displayName var.
+ * @return				true if FindMap returns FindMap_Found, FindMap_FuzzyMatch, or
+ * 						FindMap_NonCanonical.
+ * 						false if FindMap returns FindMap_PossiblyAvailable or FindMap_NotFound.
+ */
+native bool GetMapDisplayName(const char[] map, char[] displayName, int maxlen);
+
 /**
  * Returns whether the server is dedicated.
  *