Updated stm32_to_json script

[katyo]

Because original script looks outdated, I reimplemented it.

Features:

• Linking existing packages and 3d models
• Separating logic and power pins to different gates/units
• Updating existing parts
• Skipping some outputs

JSON outputs:

• Entity
• Part
• Unit(s)

[carrotIndustries]

The original script outputs json that's to be imported into the part wizard for manual adjustments. Either keep that option in your script or add your script as a new one.

[katyo]

The original script outputs json that's to be imported into the part wizard for manual adjustments. Either keep that option in your script or add your script as a new one.

Hmm... It seems I failed to get it working.

[katyo]

@carrotIndustries
May be it will be appropriate to move this PR to horizon-pool repo?