Refactor "Display To Public" functionality

Refactor "Display To Public" functionality that allows user to select fields that will be displayed on his Public Profile.

[B]Currently:[/B]

DisplayToPublic status is stored in PersistentSession table as 1 row for each variable per User. Resulting in huge data amounts.

[B]Solution:[/B]

Add new user field "DisplayToPublic" in PortalUser table and store all field
names, that should be visible on Public profile page.