Add cells extraction CLI

[dvp2015]

We often need to extract subset of cells from a model. These cells may represent a new model to be used for some specific tasks, typically not related to transport. For instance, to estimate activation for some selected components using R2S or visualize the components converting them to STP and then to STL files.
The task is repeatable as a routine, so special CLI for that is of certain value. Also this function may be exposed as python API for more versatile cells selection.

For CLI it would be enough to select cells:

• by list of numbers or ranges of numbers,
• by regex to match the cell $-comments

Exclusions from selected cells is to be supported by analogous specifications (numbers or regex).
The function is to be configured with external toml file. The inclusion and exclusion lists of numbers can be specified in separate files.