More UI fixes

• Hide browser window when an item is opened
• Correctly reset the active item after an item is launched

UI Fixes

• Show icon for browser items
• Fix file preview for files opened in VSCode
• Enable webview tag to display browser preview

UI Update

Remove helm as an option in the launcher dropdown.

Study prototype

This is the version of the application used in our controlled study. Lot's of values are hard-coded and the code needs to be re-factored somewhat.

Mock UI

Add mock UI.