fix(ocpi-2.1.1): align domain models with the specification

[juherr]

Summary

• align OCPI 2.1.1 CDR, Session, Command, Token, Credentials, Location, Tariff, and Version domain models with the reference specification
• update validation and both Jackson and kotlinx.serialization integrations for the corrected wire contracts
• add cross-serializer compliance coverage for corrected shapes, enum values, and identifier limits

Breaking changes

This intentionally removes OCPI 2.2-only fields and values from the 2.1.1 public API and replaces the multi-role credentials contract with the flat OCPI 2.1.1 shape.

Validation

• ./gradlew build
• targeted OCPI 2.1.1 tests with Jackson and kotlinx.serialization
• ktlint checks for the core and serialization integration modules

fix #200

[sonarqubecloud]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[lilgallon]

Looks great, thanks :)