UPDATE: bump mypy version

UPDATE: include serialization.py in mypy test

UPDATE: Primitive is a union type now

UPDATE: f-string formatted values are explicitly converted into strings

REMOVE: field_sorter() had no real usage

UPDATE: from_primitive() takes a generalized Primitive value

UPDATE: narrow Primitive value type within from_primitive()

FIX: BlockFrostChainContext constructor to have an empty string default value

Author: daehan-koreapool