XL9535 I/O Expander

[mreditor97]

What does this implement/fix?

This implements support for the XL9535 I/O Expander.

This is the first part of my attempt to support the Lilygo T-RGB 2.1" Round Display within the ESP Home platform

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): fixes

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#2949

Test Environment

• ESP32
• ESP32 IDF
• ESP8266
• RP2040

Example entry for config.yaml:

# Example configuration entry
xl9535:
  - id: xl9535_hub
    address: 0x20
  
# Individual outputs
switch:
  - platform: gpio
    name: XL9535 Pin 0
    pin:
      xl9535: xl9535_hub
      number: 0
      mode:
        output: true
      inverted: false

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.

[probot-esphome]

Hey there @mreditor97,
Thanks for submitting this pull request! Can you add yourself as a codeowner for this integration? This way we can notify you if a bug report for this integration is reported.
In __init__.py of the integration, please add:

CODEOWNERS = ["@mreditor97"]

And run script/build_codeowners.py

_{^{(message by NeedsCodeownersLabel)}}