Check-In risk level transmission (EXPOSUREAPP-5770) (#2641)

* Refactoring

* lint

* Put submission steps together

* Default values

* Fix tests

* klint

* Prepare test data

* Docs and improvements

* Risk transmission tests

* Negative age

* Simplify default value logic

* CheckIn assertions

* Use specific date

* Improvements of logging and mapping

* Mark the class with Singleton - move log statement

* Assertion for splitted check-in

* Adopt CheckIn changes

* Derive 10 minutes intervals

* Map location bytes as per specs

* Base64 of test trace locations

* Create specific data class as deriveTime output

Co-authored-by: harambasicluka <64483219+harambasicluka@users.noreply.github.com>
Co-authored-by: Lukas Lechner <lukas.lechner@sap.com>