[TimeBoxed]Support Python 3.10

[mnozhchev]

What is the feature request? What problem does it solve?
pip install quickstart-vdk fails on Python 3.10 with a very uninformative message. Also README.md says that vdk requires "Python 3.7+" which implies that Python 3.10 is supported.

Suggested solution
Test vdk on Python 3.10 and, then, update the setup.cfg metadata to include 3.10.

Additional context

[antoniivanov]

There are 3 components that need to be changed. We may split it into 3 sub-issues when starting to work on that.

vdk-core:

Test vdk on Python 3.10:
Add Gitlab CI Job (similar to the other ones for 3.7-3.9) vdk-core-simple_func_test_with_py310 and vdk-core-build_with_py310 (to vdk-core file -https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-core/.gitlab-ci.yml)
and if PR passes that's enough

vdk plugins:

The same as vdk-core goes for each plugin. This means editing each plugin CI file: For example https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-core/plugins/vdk-postgres/.plugin-ci.yml

vdk-control-cli:
Similarly new CI job "vdk-control-cli-build-with-py310" :
https://github.com/vmware/versatile-data-kit/blob/main/projects/vdk-control-cli/.gitlab-ci.yml

I don't anticipate anything to break. But you never know.