2.0.0 release

• Full type hints
• Docstrings better detail exceptions raised and behaviour
• Better performance when dealing with long responses
• Removal of socket lock, instead this is now better documented
• Handling of null bytes in responses is improved
• Construct is no longer a dependency
• receive_packets renamed to receive_packet to reflect new behaviour
• Dependency on anyio for async is now handled formally
• Migrated to pyproject.toml style packaging
• Relicensed to LGPLv2.1