Add support for RX5808

[spikeygg]

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

I'd like to build a lap timer with ESPHome to measure the broadcast of 5.8GHz signals from drones. There are quite a few build videos online for constructing these with ESP32s (for example) and many seem to use the RX5808 sensor. Sadly, this sensor is not supported in ESPHome at this time.

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

I'm into flying FPV drones and I'm getting better ... to the point where I want to try flying RaceGOW which is racing small drones through a path using a makeshift PVC constructed course. Like this. for example:

When you have the course, you put a lap timer at the START/FINISH of the course and every time your drone passes it, the lap time is logged and announced. There are firmware packages out there for handling this but I thought if we could integrate it into ESPHome+Home Assistant then logging and automations for announcing the time, and possibly other cool things should be pretty easily obtained!

Additional context

Here's a very short datasheet I found for the device: https://www.foxtechfpv.com/product/5.8G%20modules/rx5808/RX5808-Spec-V1.pdf I bought a few of these RX5808 sensors from AliExpress, they're about $7 each.