feat(previews): Enable migration from Faust

[ahuseyn]

HWP Previews should be automatically configured to default Faust previews settings in order to facilitate the migration.

If Faust is enabled in WP instance HWP Previews should be configured as below:

• - Previews enabled
• - URL structure set to Faust preview URL structure
• - Previews functionality of Faustjs disabled
• - User is being informed about the migration