hosted projects (#8627)

- **Allow joining a hosted project**

You can't yet do anything in a hosted project, but you can join it and
look how empty it is.

Release Notes:

- N/A

crates/channel/src/channel.rs

@@ -11,7 +11,7 @@ pub use channel_chat::{
     mentions_to_proto, ChannelChat, ChannelChatEvent, ChannelMessage, ChannelMessageId,
     MessageParams,
 };
-pub use channel_store::{Channel, ChannelEvent, ChannelMembership, ChannelStore, HostedProjectId};
+pub use channel_store::{Channel, ChannelEvent, ChannelMembership, ChannelStore};
 
 #[cfg(test)]
 mod channel_store_tests;

crates/channel/src/channel_store.rs

@@ -3,7 +3,9 @@ mod channel_index;
 use crate::{channel_buffer::ChannelBuffer, channel_chat::ChannelChat, ChannelMessage};
 use anyhow::{anyhow, Result};
 use channel_index::ChannelIndex;
-use client::{ChannelId, Client, ClientSettings, Subscription, User, UserId, UserStore};
+use client::{
+    ChannelId, Client, ClientSettings, HostedProjectId, Subscription, User, UserId, UserStore,
+};
 use collections::{hash_map, HashMap, HashSet};
 use futures::{channel::mpsc, future::Shared, Future, FutureExt, StreamExt};
 use gpui::{
@@ -27,9 +29,6 @@ pub fn init(client: &Arc<Client>, user_store: Model<UserStore>, cx: &mut AppCont
     cx.set_global(GlobalChannelStore(channel_store));
 }
 
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
-pub struct HostedProjectId(pub u64);
-
 #[derive(Debug, Clone, Default)]
 struct NotesVersion {
     epoch: u64,