[Quest API] Add Silent Saylink Methods to Perl/Lua (#4177)

# Perl
- Add `quest::silent_saylink(text)`.
- Add `quest::silent_saylink(text, link_name)`.

# Lua
- Add `eq.silent_say_link(text)`.
- Add `eq.silent_say_link(text, link_name)`.

# Notes
- Allows operators to more easily use silent saylinks without an optional silent parameter in the traditional saylink methods.
- Sets `silent` parameter default to `false` so we do not need to pass `false` when we are not using a a silent saylink.
- Changes all places that used `EQ::SayLinkEngine::GenerateQuestSaylink` to `Saylink::Create` where possible.
- Removed `questmgr` method that is no longer necessary.
- Cleaned up Lua methods to use the strings directly instead of building one out.

zone/questmgr.cpp

@@ -3869,13 +3869,6 @@ void QuestManager::FlagInstanceByRaidLeader(uint32 zone, int16 version)
 	}
 }
 
-std::string QuestManager::saylink(char *saylink_text, bool silent, const char *link_name)
-{
-	QuestManagerCurrentQuestVars();
-
-	return Saylink::Create(saylink_text, silent, link_name);
-}
-
 std::string QuestManager::getcharnamebyid(uint32 char_id) {
 	std::string res;
 	if (char_id > 0) {