remove the now obsolete method "asPythonArgumentList"

necessary to guard following refactorings

because of this it became necessary to move PyFmt to "Base" to avoid circular lib references

A sample builder shall get the parameter values already at construction time, not afterwards.

This also eliminates the usage of registered parameters

...to encapsulate knowledge where it really belongs to

there may be a different way; for simplicity, I chose this way