Folders step 3: Folders UI

[kuzmany]

Based on https://docs.google.com/document/d/1nJxRDGslOg5aIxoLyK2RwGz1zek9i_DD9L555vnDHN4/edit

Integrate folder structure to bundles to UI.

Should contain:

• folders on the top of the section of bundles from level 1 + number of entities include in the folders
• last modified entities from all folders
• new column for table view folders/clickable labels to certain folder

[RCheesley]

Pinging @mautic/ux-ui-tiger-team for their feedback/thoughts.