Pysteamauth

- Added new proto files versions
- Added stubs for proto files
- New `SteamQR` class for authorization using QR code
- Added ability of authorization with specified platform (WebBrowser, Client, Mobile)
- Cookie storage uses platform value as part of key
- Default cookie storage key is `{steamid}_{platform}`
- Authorization requires steamid of Steam account
- Changed method of getting cookies
- Added `BaseSteam` class

- `get_steam_guard` method is classmethod now
- Removed docstrings
- Added new properties to Steam class
- Removed `AuthenticatorData` schema
- Removed `SteamAuthorizationStatus` schema
- Removed `ServerTimeResponse` schema
- Removed `get_host_from_url` function
- Initialize `steamid` if it doesn't specify
- Steam class now accepts objects of `BaseRequestStrategy` and `BaseCookieStorage`

- Removed default value for `domain` parameter in cookie storage

- Removed useless exceptions

- Fixed `check_http_status` method

- Updated protobuf version