Channel chat: Add edit message (#9035)

**Summary**:
- Removed reply message from message_menu
- Made render_popover_buttons a bit more reusable
- Fixed issue that you can't close the reply/edit preview when you are
not focusing the message editor
- Notify only the new people that were mentioned inside the edited
message

**Follow up**
- Fix that we update the notification message for the people that we
mentioned already
- Fix that we remove the notification when a message gets deleted.
  - Fix last acknowledge message id is in correct now

**Todo**:
- [x] Add tests
- [x] Change new added bindings to the `Editor::Cancel` event.

Release Notes:

- Added editing of chat messages
([#6707](https://github.com/zed-industries/zed/issues/6707)).

<img width="239" alt="Screenshot 2024-03-09 at 11 55 23"
src="https://github.com/zed-industries/zed/assets/62463826/b0949f0d-0f8b-43e1-ac20-4c6d40ac41e1">
<img width="240" alt="Screenshot 2024-03-13 at 13 34 23"
src="https://github.com/zed-industries/zed/assets/62463826/d0636da2-c5aa-4fed-858e-4bebe5695ba7">

---------

Co-authored-by: Bennet Bo Fenner <53836821+bennetbo@users.noreply.github.com>
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/collab_ui/src/chat_panel/message_editor.rs

@@ -37,6 +37,7 @@ pub struct MessageEditor {
     mentions_task: Option<Task<()>>,
     channel_id: Option<ChannelId>,
     reply_to_message_id: Option<u64>,
+    edit_message_id: Option<u64>,
 }
 
 struct MessageEditorCompletionProvider(WeakView<MessageEditor>);
@@ -131,6 +132,7 @@ impl MessageEditor {
             mentions: Vec::new(),
             mentions_task: None,
             reply_to_message_id: None,
+            edit_message_id: None,
         }
     }
 
@@ -146,6 +148,18 @@ impl MessageEditor {
         self.reply_to_message_id = None;
     }
 
+    pub fn edit_message_id(&self) -> Option<u64> {
+        self.edit_message_id
+    }
+
+    pub fn set_edit_message_id(&mut self, edit_message_id: u64) {
+        self.edit_message_id = Some(edit_message_id);
+    }
+
+    pub fn clear_edit_message_id(&mut self) {
+        self.edit_message_id = None;
+    }
+
     pub fn set_channel(
         &mut self,
         channel_id: ChannelId,