fix: error message for new pfs columns

[frodehk]

ECALC-1267

Have you remembered and considered?

• I have used conventional commits syntax (if you squash, make sure that conventional commit is used)
• I have included the Jira issue ID somewhere in the commit body (ECALC-XXXX)

Why is this pull request needed?

Error occurs when creating error message related to wrong category for power from shore columns/variables (CABLE_LOSS and MAX_USAGE_FROM_SHORE only valid for category POWER_FROM_SHORE)

What does this pull request change?

Use model_fields to obtain titles/names in error message.

Issues related to this change:

https://equinor-ecalc.atlassian.net/browse/ECALC-1267?atlOrigin=eyJpIjoiZWMzNDlhNTI5NmM0NDkwMTgwNTljZTM1ZmQ3NWNkM2QiLCJwIjoiaiJ9

[TeeeJay]

possible to have a small test for this?

[frodehk]

Sorry, didn´t see your comment before merging:-) Will have a look at the testing. Challenge is that the validation is different in cli vs web.