Add support for auto-closing of JSX tags (#25681)

Closes #4271

Implemented by kicking of a task on the main thread at the end of
`Editor::handle_input` which waits for the buffer to be re-parsed before
checking if JSX tag completion possible based on the recent edits, and
if it is then it spawns a task on the background thread to generate the
edits to be auto-applied to the buffer

Release Notes:

- Added support for auto-closing of JSX tags

---------

Co-authored-by: Cole Miller <cole@zed.dev>
Co-authored-by: Max Brunsfeld <max@zed.dev>
Co-authored-by: Marshall Bowers <git@maxdeviant.com>
Co-authored-by: Mikayla <mikayla@zed.dev>
Co-authored-by: Peter Tripp <peter@zed.dev>

crates/multi_buffer/src/multi_buffer.rs

@@ -1071,6 +1071,11 @@ impl MultiBuffer {
         self.history.start_transaction(now)
     }
 
+    pub fn last_transaction_id(&self) -> Option<TransactionId> {
+        let last_transaction = self.history.undo_stack.last()?;
+        return Some(last_transaction.id);
+    }
+
     pub fn end_transaction(&mut self, cx: &mut Context<Self>) -> Option<TransactionId> {
         self.end_transaction_at(Instant::now(), cx)
     }