Fixes default permissions urls and adds return value to update endpoints

[shinchris]

Default permissions urls for update and delete were missing an 's' after the content types. Also noticed that the update permission methods weren't returning the response from server, while the delete methods were unnecessarily returning something.

Changes:

• Corrected URLs for update and delete default permissions by appending an s to the content type
• Removed return statements for the delete methods
• Added return statements for the update methods
• Fixed delete default permissions test and added a update default permissions test

[shinchris]

I'm also adding some samples. Will push it as soon as it's done.
Since we don't have docs yet, the samples should hopefully help in the meantime.

[t8y8]

Can you verify it runs on a real server internally (one with Catalog enabled?) -- I'm 99% sure I did back in the day but apparently I missed something.