feat: adapt to v0

[null8626]

The following pull request is a toned down version of #79. This pull request adapts the SDK to v0's latest changes.

Other notable changelogs:

• Instead of naive variable-based deserialization, every structure now has a clear deserialization mechanism. This also allows for __slots__ in every structure, which saves memory space.
• Make the latest version 1.5.0 instead of 3.0.0.
• Add deprecation warnings for usage of obsolete parameters.
• Remove support for Python 3.9, which is EOL in October 2025.
• Add support for Python 3.14.
• Bump aiohttp dependency to version 3.13.0.
• Overhaul docstrings to use sphinx's preferred format.
• Remove unused exceptions.
• Change the Discord invite link to the non-vanity one.
• Use list[] and dict[] over the deprecated t.List[] and t.Dict[] for type annotations.