New function in hidden for structural meta information of the DB

If you can remember i wrote this comprehensive overview view for the database. I would like to create a new view with it for the user to see how the data base is structured in schema public. Further I could then easily use it for the PET as i only need to call the view in R to work with it. Do you see benefit and sense to in it. I will create a new scr in branch dev in installation so you can have a look at it in the tethys_test. Execution rights would need to be tethys_admin i guess.