Add communication with simulator

[paulstraw]

Is your feature request related to a problem? Please describe.
This would certainly make development easier when you only have one Playdate! Among other benefits like the ability to have "dedicated servers" running actual PD code.

Describe the solution you'd like
Some discussion: https://discord.com/channels/675983554655551509/1173443567730032730/1173466464548835349