feat: add identity and business verification trigger

[cursor]

Fixes

Adds triggerIdentityOrBusinessVerification for the dedicated POST /v1/verifications/trigger endpoint while preserving the existing type-in-path trigger.

Documentation: trolley/developer-documentation#221

Checklist

• I acknowledge that all my contributions will be made under the project's license
• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have titled the PR appropriately
• I have updated my branch with the main branch
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation about the functionality in the appropriate .md file
• I have added inline documentation to the code I modified

Validation: mvn -Dtest=VerificationGatewayTest test (1 passing) and mvn compile.