Add CRUD entry points for "full" resources

[mbarto]

Some actions that should be execute as one transaction are currently not possible. Usually when we handle a resource, we have also to handle permissions, categories and linked resources.
We need CRUD actions to do this in a single transaction.

Create:

• create category if missing
• create the resource
• set the resource permissions
• create linked resources recursively (with their permissions and categories)

Read:

• get the resource with its permissions and the linked resources

Update:

• update the resource
• set the resource permissions
• update linked resources recursively (with their permissions)

Delete:

• delete the resource
• dekete linked resources recursively