Fix: config.py: implement _ArrayFieldType.size_is_dynamic()
Fix: config.py: implement _ArrayFieldType.size_is_dynamic()

An array field type's size is dynamic if its element field type is.

Signed-off-by: Philippe Proulx <2096628897b40c93960fdd9e24c9c883a54d4fe9@gmail.com>

efficios/barectf,efficios/barectf