* Initialize left menu react migration and migration download menu UI to react
* Add test case to DownloadMenu react component
* Update test description and add an href check to one of the download link
* Extract storybook document mock to its own fixture file
* Add mockCompileOnLoad config on storybook editor scope
- if mockCompileOnLoad: true (default), then the default compile mock will be used
- If mockCompileOnLoad: false, then we have to provide a compile mock on the storybook component
* Create download menu storybook component
* Use a single "editor-left-menu" controller on the editor left menu migrations
* Remove the form import from the react version of the left menu
* Change inline style to utility class name
GitOrigin-RevId: 5357c7bfc78bf40f52b9b308df8f2b60d793fbf7
