Provide some way for cleaning RecurringJob.Instance

Issue
I have integration tests with separare database instances for write, read in docker so they up one by one
Issue is when It switch between database and reset database connection - Recurring Job can't handle connection change because it's has instance which copy old static JobStorage.Current to his variable

Start by tracing RecurringJob.Instance and how it captures JobStorage.Current during database connection changes. Define how the recurring-job instance should be cleaned or recreated after a storage reset, then verify the behavior with the described integration-test setup using separate write and read database instances.

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