Dynamic enum values lost when editing code

Dynamic enum values reset to 0 once a change was made in the code.

To Reproduce

1. Go to https://makecode.com/playground#language-create-enums
2. Click 'Run'
3. Add a 'Show $color' block from the 'Language' menu and give it a non-zero value (Blue or Yellow)
   4.Switch to the JavaScript view
4. Add an empty line at the end of the code
5. Switch back to Blocks view
6. The block displays the value Red (0), while the code shows otherwise
7. When in actual projects, saving and reloading resets the value to 0 also in the code view resulting in real data loss
   Expected behavior
8. Blocks and code values should be in sync
9. Values should not be lost after reload

Start by reproducing the issue in the linked MakeCode enum playground, comparing the Blocks and JavaScript views after changing a dynamic enum value and reloading. Trace the code that serializes and restores enum values during the Blocks/JavaScript transition and project reload. Done means non-zero values remain synchronized in both views and survive saving and reloading.