Fix excluded file creation (#12620)

Fixes https://github.com/zed-industries/zed/issues/10890

* removes `unwrap()` that caused panics for text elements with no text,
remaining after edit state is cleared but project entries are not
updated, having the fake, "new entry"
* improves discoverability of the FS errors during file/directory
creation: now those are shown as workspace notifications
* stops printing anyhow backtraces in workspace notifications, printing
the more readable chain of contexts instead
* better indicates when new entries are created as excluded ones


Release Notes:

- Improve excluded entry creation workflow in the project panel
([10890](https://github.com/zed-industries/zed/issues/10890))

crates/worktree/src/worktree_tests.rs

@@ -1212,6 +1212,7 @@ async fn test_create_directory_during_initial_scan(cx: &mut TestAppContext) {
         })
         .await
         .unwrap()
+        .to_included()
         .unwrap();
     assert!(entry.is_dir());
 
@@ -1268,6 +1269,7 @@ async fn test_create_dir_all_on_create_entry(cx: &mut TestAppContext) {
         })
         .await
         .unwrap()
+        .to_included()
         .unwrap();
     assert!(entry.is_file());
 
@@ -1310,6 +1312,7 @@ async fn test_create_dir_all_on_create_entry(cx: &mut TestAppContext) {
         })
         .await
         .unwrap()
+        .to_included()
         .unwrap();
     assert!(entry.is_file());
 
@@ -1329,6 +1332,7 @@ async fn test_create_dir_all_on_create_entry(cx: &mut TestAppContext) {
         })
         .await
         .unwrap()
+        .to_included()
         .unwrap();
     assert!(entry.is_file());
 
@@ -1346,6 +1350,7 @@ async fn test_create_dir_all_on_create_entry(cx: &mut TestAppContext) {
         })
         .await
         .unwrap()
+        .to_included()
         .unwrap();
     assert!(entry.is_file());
 
@@ -1673,7 +1678,7 @@ fn randomly_mutate_worktree(
             );
             let task = worktree.rename_entry(entry.id, new_path, cx);
             cx.background_executor().spawn(async move {
-                task.await?.unwrap();
+                task.await?.to_included().unwrap();
                 Ok(())
             })
         }