The roles an application holds as itself, and those it could be granted.
Parameters
identifier: any
the application
Returns {held:any;offerable:any}
{ held, offerable }: held rows carry name, id,
displayName, application (whose role it is, or empty for a
realm-wide one), carriedAs and permissions; offerable is role
names
The roles an application holds as itself, and those it could be granted.