Add flags to enable strict stable API

[Alexey Palazhchenko]

Our examples for .NET, Python and Java should accept -strict or --strict (whatever is easier) boolean flag that would enable strict Stable API.

We should use appropriate standard libraries for those languages for flags / arguments parsing, not accept "raw" CLI parameters directly (i.e., in Python, we should use argparse module instead of accessing sys.argv directly).

Tasks

Beta Give feedback

1. allow enabling of strict API for .NET example
2. allow enabling of strict API for Java example
3. allow enabling of strict API for Python example

Dance CI changes are not in scope.