[Quest API] Simplify bulk Scribe and Train logic. (#1660)

* [Quest API] Simplify bulk Scribe and Train logic.
- Add $client->GetFreeDisciplineSlot(starting_slot) to Perl.
- Add $client->ScribeSpells(min_level, max_level) to Perl.
- Add $client->LearnDisciplines(min_level, max_level) to Perl.
- Add client:GetNextAvailableDisciplineSlot(starting_slot) to Lua.
- Add client:ScribeSpells(min_level, max_level) to Lua.
- Add client:LearnDisciplines(min_level, max_level) to Lua.
Convert quest::scribespells() and quest::traindisc() to use new ScribeSpells and LearnDisciplines methods for consistency.

* Update command.cpp

zone/spells.cpp

@@ -6257,5 +6257,12 @@ bool Client::IsLinkedSpellReuseTimerReady(uint32 timer_id)
 	return GetPTimers().Expired(&database, pTimerLinkedSpellReuseStart + timer_id, false);
 }
 
+int Client::GetNextAvailableDisciplineSlot(int starting_slot) {
+	for (uint32 index = starting_slot; index < MAX_PP_DISCIPLINES; index++) {
+		if (!IsValidSpell(GetPP().disciplines.values[index])) {
+			return index;
+		}
+	}
 
-
+	return -1; // Return -1 if No Slots open
+}