Remove support for group calls and guild sync

Calls and guild sync are essentially leftovers from selfbot support
removal, the former moreso.

Removes the following `model::event` structs:

- CallCreateEvent
- CallDeleteEvent
- CallUpdateEvent
- GuildSyncEvent

which also removes the following `model::event::Event` variants:

`client::gateway::Shard::sync_calls` has been removed.

The following `client::Client` methods have been removed:

- `on_call_create`
- `on_call_delete`
- `on_call_update`
- `on_guild_sync`

Removes the following items on `ext::cache::Cache`:

```
ext::cache::Cache::{
    // fields
    calls,
    // methods
    get_call,
    update_with_call_create,
    update_with_call_delete,
    update_with_call_update,
    update_with_guild_sync,
}
```

Voice structs and methods now take solely a `guild_id` instead of a
`target`, due to the handling of 1-on-1 and group calls being removed.

This continues off commit d9118c0.<Paste>

1 files changed, 5 insertions, 7 deletions

diff --git a/src/ext/voice/threading.rs b/src/ext/voice/threading.rs
index 0aaafba..3986f48 100644
--- a/src/ext/voice/threading.rs
+++ b/src/ext/voice/threading.rs
@@ -1,19 +1,17 @@
 use std::sync::mpsc::{Receiver as MpscReceiver, TryRecvError};
 use std::thread::Builder as ThreadBuilder;
 use super::connection::Connection;
-use super::{Status, Target};
+use super::Status;
 use ::internal::Timer;
+use ::model::GuildId;
 
-pub fn start(target_id: Target, rx: MpscReceiver<Status>) {
-    let name = match target_id {
-        Target::Channel(channel_id) => format!("Serenity Voice (C{})", channel_id),
-        Target::Guild(guild_id) => format!("Serenity Voice (G{})", guild_id),
-    };
+pub fn start(guild_id: GuildId, rx: MpscReceiver<Status>) {
+    let name = format!("Serenity Voice (G{})", guild_id);
 
     ThreadBuilder::new()
         .name(name)
         .spawn(move || runner(rx))
-        .expect(&format!("[Voice] Error starting target: {:?}", target_id));
+        .expect(&format!("[Voice] Error starting guild: {:?}", guild_id));
 }
 
 fn runner(rx: MpscReceiver<Status>) {