Error 404 and 422

[FabrizioMoggio]

Problem description

• 404 UNKNOWN_APPLICATION_IDENTIFIER is not relevant for this API
• 422_MISSING_IDENTIFIER is not allined with in CAMARA_common.yaml (https://github.com/camaraproject/Commonalities/blob/main/artifacts/CAMARA_common.yaml)
• 422 is not used

Expected behavior

• remove 404 UNKNOWN_APPLICATION_IDENTIFIER
• align 422_MISSING_IDENTIFIER with CAMARA_common.yaml
• associate 422 with an endpoint or remove it