TestCertificate Repository polishing & improvements (EXPSUREAPP-7505) (#3373)

* fixed components path

* Improve error handling and fix crash due to uncaught throwable.

* fixed dcc server di

* + api test

* Add wrapper class around TestCertificateContainer to include valuesets on repository level already.

* Provide data extractor on container creation to prevent accidental early access of `lateinit var`

* Improve comments.

* Add missing click listener and refactor deep nesting.

* LINTs

Co-authored-by: chris-cwa <chris.cwa.sap@gmail.com>
Co-authored-by: harambasicluka <64483219+harambasicluka@users.noreply.github.com>
Co-authored-by: Mohamed Metwalli <mohamed.metwalli@sap.com>