Nextion

What's Changed
* Refactor codebase and update dependencies by yozik04 in https://github.com/yozik04/nextion/pull/32

**Full Changelog**: https://github.com/yozik04/nextion/compare/1.8.1...2.0.0

Fixed
- `Current Page Number` (`sendme`) response was not parsed correctly. Thanks sputnik-dancarroll 25 for the fix.

Improved
- Support for async event_handler. 24 See updated example in the [README.md](https://github.com/yozik04/nextion/tree/1.8.0)

Improved
- Smart parsing of fixed length packets. Fixes issue with negative integers 18.

Other
- protocol.py was split into multiple files. Classes should still be available in old places.

Improved
- Compatibility with Nextion 1.61.1 (10)
- Suppressing non critical errors during upload (11 )

Added
- Firmware uploading console script: `nextion-fw-upload`
- Different character encodings 4
- Try both regular connect and connect using broadcast address
- During connect try to exit active Protocol Reparse and return to passive mode (found in spec https://nextion.tech/2017/12/08/nextion-hmi-upload-protocol-v1-1/)

Improved
- Better reconnect on timeouts