Control flow support for Python 3.9 +

[dgarijo]

Unfortunately, cdmcfparser does not have support for Python 3.9+ yet, and we get an error dumping the core.

• Alternative 1: fork their repo and fix it/wait for them to produce an update
• Alternative 2: Implement another control flow library.

[dgarijo]

It was suggested that cdmpyparser may be an alternative to address this. We will have to investigate further.

[dgarijo]

See https://github.com/SergeySatskiy/cdm-flowparser/issues/7#issuecomment-1033179389

[dgarijo]

For the moment the solution for Python 3.10+ is to drop support for cmdcfparser