Code view likely references old script objects after hot reload

If a script is changed as the result of a hot reload, the `Script` object needs to be re-retrieved to get its updated VM service object ID as the internal `Script` object has been replaced by the VM.

Some issues that are likely related to this are:
- Code coverage and profiler hits disappear after a hot reload
- Rendered sources are out of date after a hot reload
- Breakpoint state isn't cleared in scripts that were hot reloaded (e.g., breakpoints are displayed even though they aren't automatically reset for the new script)

Start by tracing the Code view's Script lookup during hot reload and how it obtains the VM service object ID. Use the reported coverage and profiler hits, rendered sources, and breakpoint state as verification points; done means these remain correct after a script is hot reloaded.

索引モデルが issue の本文から書いたものです。