Emylo RF codes

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

When using a receiver and or a transmitter it could be useful to be able to de-/en-code signals according to Emylo protocol.
For transmission it's already possible (but not easy) via raw codes, but decoding an unknown transmitter is quite hard (especially in a RF-noisy environment).

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

Emylo transmitters are readily available, even models that do not require batteries (energy-harvesting).
I tried with raw codes, but there's too much noise and log is flooded by unrelated noise (even when I do not connect the antenna to rx module).
Already tried enabling all other decoders but no luck.

**Additional context**

The protocol is quite simple:
- 9ms low (start)
- 24 "slots", 1.5ms each:
- '1' bit is 1.15ms high / 350us low
- '0' bit is 350us high / 1.15ms low
- the first 20 slots are the address, the remaining 4 bits the pressed key(s)
- at the end signal goes high again

Hope that's enough, else I'll have to take out the scope :)
Too bad I'm not familiar enough with EspHome internals to try implementing it myself :(

Start with ESPHome's raw-code handling and existing receiver/transmitter decoder entry points, comparing how other decoders process signal timings. Done means Emylo signals can be decoded reliably despite RF noise and supported for transmission without requiring raw codes; the issue does not name specific files or tests.

Written by the indexing model from the issue text.