Resolves issues 1540/1541, Migrate RegistryOrg get functions to use baseOrg/

[emathew5]

Closes Issue 1540 and 1541

Summary

Migrated RegistryOrg/ GET endpoints to use the baseOrg schemas, making use of the discriminator based repositories. Previously RegistryOrg/ diverged from the /registry/ return values as seen below

Field	RegistryOrg	/registry/
cve_program_org_function	Enum with strict values	Not present
authority	{ active_roles: [String] }	[String] (flat array)
users	[String]	{ type: [String], set: toUndefined }
admins	Inside contact_info.admins	Top-level admins field

Now, both endpoints will return the same values.

And the cve_program_org_function is no longer needed since the mongoose __t discriminator fields replace the need for it.