Make the Tags based on Object Definition

[schaefa]

Tags are based on a fixed definition in Admin. The Tag should be based on an Object Definition to make the dynamic

[schaefa]

As of now the Tags are based on an OD in apps but the handling in the Objects is a little bit confusing.
If we use a Node Type for Tags then we can make the handling cleaner as we can define what node types a folder can contain.
Custom Tags should also be based on the Base Tag OD so that the base fields are provided.