Add command permission checks

Level 0: Every user - Public commands
Level 1: Guild owners or members with respective admin role - Elevated guild commands
Level 2: Global admins - Every command including levels below

util/guilds.js

@@ -0,0 +1,23 @@
+const { Guild } = require("../models");
+
+module.exports = {
+    name: "GuildUtils",
+    getProperty: async function(guildId, property) {
+        let guild = await Guild.findOne({
+            where: {
+                guildId: guildId
+            }
+        });
+        return property ? guild[property] : guild;
+    },
+
+    setProperty: async function(guildId, property, value) {
+        let guild = await Guild.findOne({
+            where: {
+                guildId: guildId
+            }
+        });
+        guild[property] = value;
+        await guild.save();
+    }
+}