Refactor workspace notifications to use explicit NotificationId type (#10342)

This PR reworks the way workspace notifications are identified to use a
new `NotificationId` type.

A `NotificationId` is bound to a given type that is used as a unique
identifier. Generally this will be a unit struct that can be used to
uniquely identify this notification.

A `NotificationId` can also accept an optional `ElementId` in order to
distinguish between different notifications of the same type.

This system avoids the issue we had previously of selecting `usize` IDs
somewhat arbitrarily and running the risk of having two independent
notifications collide (and thus interfere with each other).

This also fixes a bug where multiple suggestion notifications for the
same extension could be live at once

Fixes https://github.com/zed-industries/zed/issues/10320.

Release Notes:

- Fixed a bug where multiple extension suggestions for the same
extension could be shown at once
([#10320](https://github.com/zed-industries/zed/issues/10320)).

---------

Co-authored-by: Max <max@zed.dev>

crates/collab_ui/src/channel_view.rs

@@ -22,6 +22,7 @@ use std::{
 };
 use ui::{prelude::*, Label};
 use util::ResultExt;
+use workspace::notifications::NotificationId;
 use workspace::{
     item::{FollowableItem, Item, ItemEvent, ItemHandle},
     register_followable_item,
@@ -269,7 +270,15 @@ impl ChannelView {
         cx.write_to_clipboard(ClipboardItem::new(link));
         self.workspace
             .update(cx, |workspace, cx| {
-                workspace.show_toast(Toast::new(0, "Link copied to clipboard"), cx);
+                struct CopyLinkForPositionToast;
+
+                workspace.show_toast(
+                    Toast::new(
+                        NotificationId::unique::<CopyLinkForPositionToast>(),
+                        "Link copied to clipboard",
+                    ),
+                    cx,
+                );
             })
             .ok();
     }

crates/collab_ui/src/notification_panel.rs

@@ -21,6 +21,7 @@ use std::{sync::Arc, time::Duration};
 use time::{OffsetDateTime, UtcOffset};
 use ui::{h_flex, prelude::*, v_flex, Avatar, Button, Icon, IconButton, IconName, Label, Tooltip};
 use util::{ResultExt, TryFutureExt};
+use workspace::notifications::NotificationId;
 use workspace::{
     dock::{DockPosition, Panel, PanelEvent},
     Workspace,
@@ -534,8 +535,10 @@ impl NotificationPanel {
 
         self.workspace
             .update(cx, |workspace, cx| {
-                workspace.dismiss_notification::<NotificationToast>(0, cx);
-                workspace.show_notification(0, cx, |cx| {
+                let id = NotificationId::unique::<NotificationToast>();
+
+                workspace.dismiss_notification(&id, cx);
+                workspace.show_notification(id, cx, |cx| {
                     let workspace = cx.view().downgrade();
                     cx.new_view(|_| NotificationToast {
                         notification_id,
@@ -554,7 +557,8 @@ impl NotificationPanel {
                 self.current_notification_toast.take();
                 self.workspace
                     .update(cx, |workspace, cx| {
-                        workspace.dismiss_notification::<NotificationToast>(0, cx)
+                        let id = NotificationId::unique::<NotificationToast>();
+                        workspace.dismiss_notification(&id, cx)
                     })
                     .ok();
             }