Updating probe tests to fix schema service related failures

There are three category of failures for schema service probe tests:

1. schema DELETE: it's not a supported scenario. Disabling it
2. schema GET for existing schemas: The authority being passed is data-partition-id. It should be osdu. Fixing the same
3. schema GET for new schemas: Logic to create new schemas was disabled hence GET call on new schema id was failing. Fixing it.

cc: @manishk @ankitsharma