[Feature] Initial user apps support (#2883)

* omg it kinda works somehow

* more things added

* a bit of xmldocs

* added interaction framework support

* working? IF

* more builder stuff

* space

* rename attribute to prevent conflict with `ContextType` enum

* context type

* moar features

* remove integration types

* trigger workflow

* modelzzzz

* `InteractionContextType`

* allow setting custom status with `SetGameAsync`

* bugzzz

* app permissions

* message interaction context

* hm

* push for cd

* structs lets goooo

* whoops forgot to change types

* whoops x2

* tweak some things

* xmldocs + missing prop + fix enabled in dm

* moar validations

* deprecate a bunch of stuffz

* disable moar obsolete warnings

* add IF sample

* Apply suggestions from code review

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

* Update src/Discord.Net.Rest/Entities/RestApplication.cs

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

---------

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

docs/guides/int_framework/samples/intro/userapps.cs

@@ -0,0 +1,19 @@
+
+// This parameteres can be configured on the module level
+// Set supported command context types to Bot DMs and Private Channels (regular DM & GDM)
+[CommandContextType(InteractionContextType.BotDm, InteractionContextType.PrivateChannel)]
+// Set supported integration installation type to User Install
+[IntegrationType(ApplicationIntegrationType.UserInstall)]
+public class CommandModule() : InteractionModuleBase<SocketInteractionContext>
+{
+    [SlashCommand("test", "Just a test command")]
+	public async Task TestCommand()
+		=> await RespondAsync("Hello There");
+
+    // But can also be overridden on the command level
+    [CommandContextType(InteractionContextType.BotDm, InteractionContextType.PrivateChannel, InteractionContextType.Guild)]
+    [IntegrationType(ApplicationIntegrationType.GuildInstall)]
+    [SlashCommand("echo", "Echo the input")]
+	public async Task EchoCommand(string input)
+		=> await RespondAsync($"You said: {input}");
+}