add tests for ydb package work with requirements from setup.py

[rekby]

Now all tests work with requirements from requirements.txt, requirements-test.txt only.

[rekby]

fired, fix simptom https://github.com/ydb-platform/ydb-python-sdk/pull/254

for the test need:

1. Build package
2. Install package to clean venv (without -e from source)
3. Execute simple script (connection to docker, stub select)

Package files difference with source folder and it can cause problem