Add routes to the API to delete entities

[benoit-cty]

We have no way to delete entities yet.

Having an entry to delete each entities is needed.

But we need a strong right management and error handling before allowing delete.

Do we want cascading delete ?

[SaboniAmine]

I propose that we limite the delete entries to experiment / project / run / emission for the moment (and in that case a cascade might be interesting).
Teams / orgs / users administration might be easier to operate with an interface and proper right management as users can belong to multiple teams/ organisations with the current implementation.