Use of new Commonalities common error types (through $ref) #246

Problem description
In Commonalities r4.4 the "GenericXXX" error schemas have been deprecated.

Expected behavior
Replace the deprecated error schemas by the new by the new common error schemas, using the $ref (external reference mechanism).

Additional context
$refs are replaced by actual schemas by release automation on publication of the final API. (a.k.a. bundling mechanism).

See also:

• https://github.com/camaraproject/Commonalities/blob/r4.4/artifacts/common/CAMARA_common.yaml
• https://github.com/camaraproject/Commonalities/tree/r4.4/artifacts/api-templates