settings: Show notification when user/project settings fail to parse (#18122)

Closes #16876

We only ever showed parsing errors, but not if something failed to
deserialize.

Basically, if you had a stray `,` somewhere, we'd show a notification
for user errors, but only squiggly lines if you had a `[]` instead of a
`{}`.

The squiggly lines would only show up when there were schema errors.

In the case of `formatter` settings, for example, if someone put in a
`{}` instead of `[]`, we'd never show anything.

With this change we always show a notification if parsing user or
project settings fails.

(Right now, the error message might still be bad, but that's a separate
change)


Release Notes:

- Added a notification to warn users if their user settings or
project-local settings failed to deserialize.

Demo:


https://github.com/user-attachments/assets/e5c48165-f2f7-4b5c-9c6d-6ea74f678683

crates/workspace/src/workspace.rs

@@ -64,7 +64,7 @@ use project::{
 use remote::{SshConnectionOptions, SshSession};
 use serde::Deserialize;
 use session::AppSession;
-use settings::Settings;
+use settings::{InvalidSettingsError, Settings};
 use shared_screen::SharedScreen;
 use sqlez::{
     bindable::{Bind, Column, StaticColumnCount},
@@ -832,6 +832,23 @@ impl Workspace {
                     }
                 }
 
+                project::Event::LocalSettingsUpdated(result) => {
+                    struct LocalSettingsUpdated;
+                    let id = NotificationId::unique::<LocalSettingsUpdated>();
+
+                    match result {
+                        Err(InvalidSettingsError::LocalSettings { message, path }) => {
+                            let full_message =
+                                format!("Failed to set local settings in {:?}:\n{}", path, message);
+                            this.show_notification(id, cx, |cx| {
+                                cx.new_view(|_| MessageNotification::new(full_message.clone()))
+                            })
+                        }
+                        Err(_) => {}
+                        Ok(_) => this.dismiss_notification(&id, cx),
+                    }
+                }
+
                 project::Event::Notification(message) => {
                     struct ProjectNotification;