Added support for sessions

[hhalina]

• fixes #

Checklist:

• [ ] Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• [ ] Add or update relevant docs, in the docs folder and in code.
• [x] Ensure PR doesn't contain untouched code reformatting: spaces, etc.
• [ ] Run flake8 and fix issues.
• [x] Run pytest no tests failed. See https://clickhouse-driver.readthedocs.io/en/latest/development.html.