Deploy Examples/Demos on actual Hardware

[PhilippvK]

The current focus of mlonmcu target software is to benchmark inference performance and validate model outputs for predefined input data.

As support for real hardware targets (e.g. esp32, esp32) was recently introduced it would be great to also use the on-board peripherals (i.e. microphone/MEMS sensors) in the deployed target software (if feasible).

The following points have to be consider:

• How to switch between benchmark/demo mode? - Command line flag? Optional run stage?
• How to design abstraction interface for target-specific code in per-model mlif_overwrite code? Multiple files? Compiler macros? (#if defined(ESPIDF_PLATFORM) && defined(RUN_DEMO) ....)
• As the demo should not end after a single inference we would need a way to keep the model running (e.g. --num=inf) - Should mlonmcu stop after flashing or also monitor the hardware?

[PhilippvK]

This got partly implemented by the esp-idf platform templates. Closing for now