Create a test with comparison vshard.call() and CRUD performance

CRUD uses `vshard.call()` for executing CRUD operations on storage. It would be interesting to compare running, for example, SELECT and INSERT via `vshard.call()` and `crud:select()` and `crud:insert()`. Comparison will show us an overhead that CRUD adds to operations on storage.

The outcome of the task is a test with at least inserts and selects using `vshard.call()` and CRUD.