Modernize implementation

[hunyadi]

• Add new class AsyncConnection with async functions that mimic original interface
• Add type hints to all member variables and functions
• Add static type checking with Mypy and Ruff
• Use idiomatic StrEnum instead of namespace classes
• Use CaseInsensitiveDict and CIMultiDict in favor of custom implementation
• Upgrade minimum required Python version to 3.10
• Upgrade Poetry to latest
• Use standard pyproject.toml rules instead of Poetry custom rules
• Add new dependency aiohttp for asynchronous HTTP calls
• Add new dependency truststore for validating certificates using OS store