[Commands] Add #sethp Command. (#1840)

- Add #sethp [Health] command to set an NPC or player's health to a specified amount, or to max if the amount is greater than their max.
- Cleanup #heal command message and logic.

zone/gm_commands/sethp.cpp

@@ -0,0 +1,55 @@
+#include "../client.h"
+
+void command_sethp(Client *c, const Seperator *sep)
+{
+	int arguments = sep->argnum;
+	if (!arguments || !sep->IsNumber(1)) {
+		c->Message(Chat::White, "Usage: #sethp [Health]");
+		return;
+	}
+
+	auto health = static_cast<int>(std::min(std::stoll(sep->arg[1]), (long long) 2000000000));
+	bool set_to_max = false;
+	Mob* target = c;
+	if (c->GetTarget()) {
+		target = c->GetTarget();
+	}
+
+	if (health >= target->GetMaxHP()) {
+		health = target->GetMaxHP();
+		set_to_max = true;
+	}
+
+	target->SetHP(health);
+	target->SendHPUpdate();
+
+	c->Message(
+		Chat::White,
+		fmt::format(
+			"Set {} to {} Health{}.",
+			(
+				c == target ?
+				"yourself" :
+				fmt::format(
+					"{} ({})",
+					target->GetCleanName(),
+					target->GetID()
+				)
+			),
+			(
+				set_to_max ?
+				"full" :
+				std::to_string(health)
+			),
+			(
+				set_to_max ?
+				fmt::format(
+					" ({})",
+					health
+				) :
+				""
+			)
+		).c_str()
+	);
+}
+