refactor loading of AS3 schema files

[simonkowallik]

The AS3Schema class objective (representing the AS3 Schema + provide validation) should be decoupled from the schema loading process for better maintainability and reduced complexity.

Goal: Loading AS3 schema files from disk should be moved out to its own class and consumed by AS3Schema.

[simonkowallik]

Specifically this code:

as3ninja/as3ninja/schema.py

Lines 76 to 121 in 05dd58a

	def _load_schema(self, version: str, force: bool = False) -> None:
	"""Private Method: load schema file from disk for specified version.
	``force`` parameter can be used to force load the schema file, even if it has been read already.
	:param version: AS3 Schema version
	:param force: Force loading of Schema even if it was loaded before (Default value = False)
	"""
	if version not in self._schemas or force:
	path = self._SCHEMA_LOCAL_FSPATH
	# build sorted list of schema files
	# intention is a sorted schema.schemas dict with newest version first
	schemalist: list = []
	versions: list = []
	for x in list(path.glob(self._SCHEMA_FILENAME_GLOB)):
	schemalist.append(str(x))
	schemalist.sort(key=self.__schemalist_sort_helper, reverse=True)
	if version == "latest":
	# schemalist is sorted, use first element as latest version
	version = schemalist[0].split("/")[-2]
	for schemafile in schemalist:
	version_file = schemafile.split("/")[-2]
	if version_file == "latest":
	continue
	versions.append(version_file)
	if version == version_file:
	try:
	self._validate_schema_version_format(version=version_file)
	with open(schemafile, "rb") as f:
	_schema = json.loads(f.read())
	self._schemas[version] = _schema
	except (AS3SchemaVersionError, ValueError):
	print(
	f"Could not read schemafile: {schemafile}, schemafile ignored.",
	file=sys.stderr,
	)
	# update versions
	self._update_versions(versions=versions)
	# (re-)sort loaded schemas according to version
	self._sort_schemas()