New API endpoints

[Oferlis]

We are trying to create a script to create automation using requests, but some endpoints or actions are missing.

• /api/automate_domains - doesn't have a create action
• endpoint for enabling datastore
• endpoint for editing instances (adding host, username, and password)
• added functionality: assigning a button to a button group, a new button created always falls under 'unassigned buttons'.
• endpoint for creating a new catalog
• endpoint for adding catalog items

[agrare]

cc @Fryguy @kbrock

[Fryguy]

Some of this is already found in open issues... I'll associate them around. Also I thought service catalogs had a endpoint, but I'll have to search.