[dwds] Implement hot reload and publish 24.3.4

- Modifies the Chrome proxy service to call a callback that the injected
client has setup in order to do a hot reload.
- This callback forwards to the restarter.
- This restarter reads from a path that Flutter tools sets up beforehand
in order to fetch the changed sources and their associated libraries.
- Issues a hot reload to DDC using that data.
- Reassembles the Flutter engine to render a frame if the extension
exists.
- Returns a ReloadReport on whether or not this operation succeeded.

dwds/CHANGELOG.md

@@ -1,5 +1,7 @@
-## 24.3.4-wip
+## 24.3.4
+
 - Added support for some debugging APIs with the DDC library bundle format. - [#2566](https://github.com/dart-lang/webdev/issues/2566)
+- Added support for hot reload using the DDC library bundle format.
 
 ## 24.3.3