Persistent pin state for Calliope/micro:bit simulation

[boonto]

Is your feature request related to a problem? Please describe.

• Currently the state of the pins (analog/digital in) in the Calliope/micro:bit simulation is reset every simulation start. This is sometimes unexpected for users and may not accurately reflect usage of the pins in real situations.

Describe the solution you'd like

• PIN states are persistent for the session.