Add method to clear a SocketGuild's user cache

src/Discord.Net.WebSocket/Entities/Guilds/SocketGuild.cs

@@ -848,7 +848,10 @@ namespace Discord.WebSocket
         /// <inheritdoc />
         public Task<int> PruneUsersAsync(int days = 30, bool simulate = false, RequestOptions options = null, IEnumerable<ulong> includeRoleIds = null)
             => GuildHelper.PruneUsersAsync(this, Discord, days, simulate, options, includeRoleIds);
-
+        /// <summary>
+        ///     Clears this guild's user cache.
+        /// </summary>
+        public void ClearUserCache() => PurgeGuildUserCache();
         internal SocketGuildUser AddOrUpdateUser(UserModel model)
         {
             if (_members.TryGetValue(model.Id, out SocketGuildUser member))