[Feature] Premium subscriptions (#2781)

* what a big commit lel, add app sub enums

* work

* ah yup lol

* `?`

* events 1

* typo

* `list` => `get` | remaining events

* add `RespondWithPremiumRequiredAsync` to interaction module base

src/Discord.Net.Interactions/InteractionModuleBase.cs

@@ -123,6 +123,10 @@ namespace Discord.Interactions
         protected virtual async Task RespondWithModalAsync<TModal>(string customId, RequestOptions options = null) where TModal : class, IModal
             => await Context.Interaction.RespondWithModalAsync<TModal>(customId, options);
 
+        /// <inheritdoc cref="IDiscordInteraction.RespondWithPremiumRequiredAsync(RequestOptions)"/>
+        protected virtual Task RespondWithPremiumRequiredAsync(RequestOptions options = null)
+            => Context.Interaction.RespondWithPremiumRequiredAsync(options);
+
         //IInteractionModuleBase
 
         /// <inheritdoc/>