As a system, during the import of results, change the TestExampleStepRepository lock to bind to specific Test Runs rather than being global

Currently, the TestExampleStepRepository lock is global, which causes some problems and delays during import execution results.  So, all threads trying to update the TestExampleStep Repository must acquire this lock.

It would be great to change the TestExampleStepRepository lock to bind to specific Test Runs instead of being global.