compat(lua50): replace % modulo operator with math.mod shim

Lua 5.0 (Vanilla 1.12) has no % operator outside string formatting; it is a
parse error. Route the 9 arithmetic modulo sites through the existing math.mod
shim (Compat/Compat.lua) so the addon parses on 5.0 through Retail.

Sites: QuestieDB daily/weekly flag tests, QuestieEvent DMF cycle math,
QuestieLearner GUID/flag math, QuestiePlayer race/class flag tests.

Modules/QuestieLearner.lua

@@ -3348,7 +3348,7 @@ local function GetIdAndTypeFromGUID(guid)
         if t then
             local low32 = tonumber(string.sub(guid, 11, 18), 16)
             if low32 then
-                local nid = low32 % 8388608
+                local nid = math.mod(low32, 8388608)
                 if nid > 0 then return nid, t end
             end
         end
@@ -3460,7 +3460,7 @@ end
 local function NpcFlagsHasQuestGiver(flags)
     if not flags then return false end
     -- bitwise AND for Lua 5.1 (no bit library guaranteed)
-    return math.floor(flags / NPC_FLAG_QUESTGIVER) % 2 == 1
+    return math.mod(math.floor(flags / NPC_FLAG_QUESTGIVER), 2) == 1
 end
 
 function QuestieLearner:OnMouseoverUnit()

Modules/QuestiePlayer.lua

@@ -100,13 +100,13 @@ end
 ---@return boolean
 function QuestiePlayer.HasRequiredRace(requiredRaces)
     -- test a bit flag: (value % (2*flag) >= flag)
-    return (not requiredRaces) or (requiredRaces == 0) or ((requiredRaces % playerRaceFlagX2) >= playerRaceFlag)
+    return (not requiredRaces) or (requiredRaces == 0) or (math.mod(requiredRaces, playerRaceFlagX2) >= playerRaceFlag)
 end
 
 ---@return boolean
 function QuestiePlayer.HasRequiredClass(requiredClasses)
     -- test a bit flag: (value % (2*flag) >= flag)
-    return (not requiredClasses) or (requiredClasses == 0) or ((requiredClasses % playerClassFlagX2) >= playerClassFlag)
+    return (not requiredClasses) or (requiredClasses == 0) or (math.mod(requiredClasses, playerClassFlagX2) >= playerClassFlag)
 end
 
 function QuestiePlayer:GetCurrentZoneId()