[SELC-6500] feat: persist billing to onboarding user request

[gianmarcoplutino]

List of Changes

• persist billing to onboarding user request

Motivation and Context

This small change was necessary because in the onboarding flow of an administrator when the contract is created there is a need to map the VAT number in the contract itself, this is only possible if we persist the Billing data

How Has This Been Tested?

the MS was started locally and a user onboarding request was executed, verifying that the VAT number was mapped in the contract

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud