Support for TCA8418 Keyboard Matrix and IO Expander

**Describe the problem you have/What new integration you would like**

I would appreciate an integration for the TCA8418. An I2C Keyboard Matrix and IO Expander.

Adafruit has a library which may help in some way: https://github.com/adafruit/Adafruit_TCA8418.

Here's the info page for their module: https://www.adafruit.com/product/4918

**Please describe your use case for this integration and alternatives you've tried:**

I have a device using an ESP32 S3 with a TCA8418 connected to a 4x4 keypad matrix. Each key has an RGB LED under it. I'd like to use this to control Home Assistant with LED feedback. Any help would be greatly appreciated!

**Additional context**

Start by reviewing the linked Adafruit_TCA8418 library and the TCA8418 module information, then examine how ESPHome integrations handle ESP32 hardware and keypad input. Define the integration scope for the 4x4 matrix and RGB LED feedback; done should mean the TCA8418 can control Home Assistant with usable key events and feedback.

Written by the indexing model from the issue text.