perl: Better function names and small refactoring

Use a better function name instead of
_perl_call_func_noargs() (_call_perl_function_with_no_arguments), and do
use its return value from the _init() and _deinit() methods.

Reported-by: Viktor Tusa <tusa@balabit.hu>
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
python: Better function names, and small refactoring

Use better function names (suggested by Viktor Tusa), and split the
python_worker_eval() function into smaller parts.

Reported-by: Viktor Tusa <tusa@balabit.hu>
Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>