Core/Misc: Add functionality to allow low level quests/kills/discoveries to grant experience

Port From (https://github.com/TrinityCore/TrinityCore/commit/502f77fe8cb082843f7eb385159dd5038a059443)

Source/WorldServer/WorldServer.conf.dist

@@ -1104,6 +1104,34 @@ MaxGroupXPDistance = 74
 
 MaxRecruitAFriendBonusDistance = 100
 
+#
+#    MinQuestScaledXPRatio
+#        Description: Min ratio of experience that a quest can grant when player level scaling is factored.
+#        Example:     50 (No less than 50% experience granted from a lower leveled quests completion)
+#                     100 (Quests always grant full experience upon completion)
+#        Default:     0 - (Quests too low may grant no experience)
+
+MinQuestScaledXPRatio = 0
+
+#
+#    MinCreatureScaledXPRatio
+#        Description: Min ratio of experience that a creature kill can grant when player level scaling is factored.  This 
+#                     will also allow spell procs to trigger, such as Drain Soul, if > 0 and exp is grantable.
+#        Example:     50 (No less than 50% experience granted from a lower leveled creature kill)
+#                     100 (Creature kills always grant full experience upon kill)
+#        Default:     0 - (Creatures too low may grant no experience)
+
+MinCreatureScaledXPRatio = 0
+
+#
+#    MinDiscoveredScaledXPRatio
+#        Description: Min ratio of experience that an area discovery event will grant when player level scaling is factored.
+#        Example:     50 (No less than 50% experience granted from discovering a new section of map)
+#                     100 (Map exploration always grant full experience upon discovery)
+#        Default:     0 - (No experience granted when discovered area is too low level)
+
+MinDiscoveredScaledXPRatio = 0
+
 #
 #    MailDeliveryDelay
 #        Description: Time (in seconds) mail delivery is delayed when sending items.