Fixed LastOpened and Favorite items to not show up in internal entity lists

[janheise]

Description

Favorite and LastOpened were registered as full entities, which led to errors on the "shared items" list for users because they are no real manageable entities and have no routes in the FE to be edited.
Solution is: not register these items as full entities.

Note: needs backport to 5.1

fixes #15574 #15638

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.