v3.0.0

bump to v3.0.0

Changed

• Complete rewrite: XSD parsing is now delegated to xsdata's SchemaParser,
  and the parsed schema is resolved into a typed, frozen Pydantic v2 model
  (OcxSchema) that serializes to JSON.
• New public API: load(source), resolve(schemas), and the model classes.
• New ocx-schema-parser export CLI.

Removed

• BREAKING: OcxParser, Transformer, LxmlParser, LxmlElement,
  SchemaHelper, OcxGlobalElement, the data_classes module, the utils
  package and the ocxdownloader sub-package (SchemaDownloader moved to
  ocx_schema_parser.downloader).
• Dependencies ocx-common, pyspellchecker and pyyaml.