Lay the groundwork for collaborating on assistant panel (#13991)

This pull request introduces collaboration for the assistant panel by
turning `Context` into a CRDT. `ContextStore` is responsible for sending
and applying operations, as well as synchronizing missed changes while
the connection was lost.

Contexts are shared on a per-project basis, and only the host can share
them for now. Shared contexts can be accessed via the `History` tab in
the assistant panel.

<img width="1819" alt="image"
src="https://github.com/zed-industries/zed/assets/482957/c7ae46d2-cde3-4b03-b74a-6e9b1555c154">


Please note that this doesn't implement following yet, which is
scheduled for a subsequent pull request.

Release Notes:

- N/A

crates/ui/src/components/icon.rs

@@ -1,6 +1,6 @@
 use gpui::{svg, AnimationElement, Hsla, IntoElement, Rems, Transformation};
 use serde::{Deserialize, Serialize};
-use strum::EnumIter;
+use strum::{EnumIter, EnumString, IntoStaticStr};
 
 use crate::{prelude::*, Indicator};
 
@@ -90,7 +90,9 @@ impl IconSize {
     }
 }
 
-#[derive(Debug, PartialEq, Copy, Clone, EnumIter, Serialize, Deserialize)]
+#[derive(
+    Debug, Eq, PartialEq, Copy, Clone, EnumIter, EnumString, IntoStaticStr, Serialize, Deserialize,
+)]
 pub enum IconName {
     Ai,
     ArrowCircle,