Test certificate repository, episode 1 (EXPOSUREAPP-7505) (#3332)

* Extend corona test data structures with digital covid certificate related properties.
+Some additional wiring, plumbing and tests for future PRs.

* LINTs

* Adjust TestRegistrationRequest to supply dcc consent and DOB on test registration.

* Remove explicit assignment, defaults are sufficient.

* A few additional unit tests to check defaults.

* DateOfBirthKey calculation, draft 1

* Fix date parser pattern.

* wip

* Adjust padding calculation to take the new dobHash into account.
Some refactoring to make it less complicated to adjust for future changes.

* klint, ofc.

* TestCertificate repo, draft1.

* DGC -> dcc

* TestCertificateRepository, draft 2

* TestCertificateRepository, draft 3

* TestCertificateRepository, draft 4

* Unit tests, draft 1.

* Add new app config parameters and implement delay mechanism.

* Unit tests, draft 2

* Unit tests, draft 3

* LINTs

* Additional unit test skeletons and wiring to setup automatic certificate creation.

* LINTs

* I don't think we need the initial delay here?

* Fix check for new unprocessed certs

* Address PR comments.

* Tests, fixes.

Co-authored-by: Mohamed Metwalli <mohamed.metwalli@sap.com>