fix(mango): covering indexes for partitioned databases
The previous work that introduced the keys-only covering indexes
did not count with the case that database might be partitioned.
And since they use a different format for their own local indexes
and the code does not handle that, it will crash.
When indexes are defined globally for the partitioned databases,
there is no problem because the view row does not include
information about the partition, i.e. it is transparent.
Add the missing support for these scenarios and extend the test
suite to cover them as well. That latter required some changes to
the base classes in the integration test suite as it apparently
completely misses out on running test cases for partitioned
databases.
4 files changed
