[Rules] Add World:Rules Rule (#4194)

* [Rules] Add World:Rules Rule

# Notes
- Adds `World:Rules` rule to take the place of the variables table value.

* Update client.cpp

* Update client.cpp

common/ruletypes.h

@@ -329,6 +329,7 @@ RULE_BOOL(World, UseItemLinksForKeyRing, false, "Uses item links for Key Ring Li
 RULE_BOOL(World, UseOldShadowKnightClassExport, true, "Disable to have Shadowknight show as Shadow Knight (live-like)")
 RULE_STRING(World, IPExemptionZones, "", "Comma-delimited list of zones to exclude from IP-limit checks. Empty string to disable.")
 RULE_STRING(World, MOTD, "", "Server MOTD sent on login, change from empty to have this be used instead of variables table 'motd' value")
+RULE_STRING(World, Rules, "", "Server Rules, change from empty to have this be used instead of variables table 'rules' value, lines are pipe (|) separated, example: A|B|C")
 RULE_CATEGORY_END()
 
 RULE_CATEGORY(Zone)

zone/client.cpp

@@ -3786,14 +3786,12 @@ void Client::GetRaidAAs(RaidLeadershipAA_Struct *into) const {
 
 void Client::EnteringMessages(Client* client)
 {
-	std::string rules;
-	if (database.GetVariable("Rules", rules)) {
-		uint8 flag = database.GetAgreementFlag(client->AccountID());
+	std::string rules = RuleS(World, Rules);
+
+	if (!rules.empty() || database.GetVariable("Rules", rules)) {
+		const uint8 flag = database.GetAgreementFlag(client->AccountID());
 		if (!flag) {
-			auto rules_link = Saylink::Silent(
-				"#serverrules",
-				"rules"
-			);
+			const std::string& rules_link = Saylink::Silent("#serverrules", "rules");
 
 			client->Message(
 				Chat::White,
@@ -3810,9 +3808,9 @@ void Client::EnteringMessages(Client* client)
 
 void Client::SendRules()
 {
-	std::string rules;
+	std::string rules = RuleS(World, Rules);
 
-	if (!database.GetVariable("Rules", rules)) {
+	if (rules.empty() && !database.GetVariable("Rules", rules)) {
 		return;
 	}