Add phone number validation for Estonian organization contacts

- Add OrgRegistrantPhoneCheckerJob execution for contact creation and update
- Rename validate_* methods to maybe_validate_* for consistency
- Add tests for phone number validation in REPP API
- Fix method naming and add proper job arguments

This ensures phone numbers are validated against company register data
for Estonian organization contacts after creation or update.

app/controllers/repp/v1/contacts_controller.rb

@@ -94,7 +94,6 @@ module Repp
         action = Actions::ContactUpdate.new(@contact, contact_params_with_address(required: false),
                                             contact_params[:legal_document],
                                             contact_ident_params(required: false), current_user)
-
         unless action.call
           handle_errors(@contact)
           return