Refactor worker scheduling (EXPOSUREAPP-6007) (#2960)

* Refactor EW&PT RiskWorker scheduling (WIP).
* PresenceTracingRiskWorkScheduler.kt and ExposureWindowRiskWorkScheduler.kt subscribe to different flows and make the decision of when to schedule the workers by themselves.

* Removed BackgroundWorkScheduler.kt

* Refactor RA&PCR test result polling scheduling (WIP)

* Add TODOs

* LINTs

* Add check for RA redeemed state after 60 days.

* Bandaid unittests

* Fix test regressions in CoronaTestStorageTest.kt

* Fix test regressions in RATestResultAvailableNotificationServiceTest.kt and PCRTestResultAvailableNotificationServiceTest.kt

* removed tests for code that was moved

* Implement failing test processor tests.

* LINTs

* updated pcr worker test

* Tweak logging.

* unit tests for pcr scheduler

* 'fixed' ktlint

Co-authored-by: chris-cwa <69595386+chris-cwa@users.noreply.github.com>
Co-authored-by: chris-cwa <chris.cwa.sap@gmail.com>