Feature/remove all of in fdo schemas

[southeo]

• removes "allof" keyword, as it requires all fields from a linked schema, even if the linked schema doesn't require it. This is undesirable behaviour. Now we duplicate fields instead of inheriting them.
• Align media object fdo profile with handle api
• Adds example schemas
• Adds FDO profile/digital object type PIDs as constants to objects we have PIDs for
• "Request" schemas include the "data"/"type"/"attribute" encapsulation of the json:api standard