Align Location Verification with guidelines for error scenarios

[jlurien]

Problem description

Current version still does not follow the recent guidelines

Possible evolution

Align codes and examples as indicated in:

• https://github.com/camaraproject/Commonalities/blob/main/documentation/API-design-guidelines.md#6-error-responses
• https://github.com/camaraproject/Commonalities/blob/main/artifacts/CAMARA_common.yaml

[jlurien]

@bigludo7 @maxl2287 please take a look to the PR as we'll have to do something similar to the other APIs. For Location Retrieval is quite similar, but Geofencing is more complex and probably have more error scenarios to cover. Thanks