Add scaffold command line interface

[bboilot-ledger]

This PR adds a command line interface for scaffold with support of the following modules:

• power (with trigger)
• io
• uart (log/repl mode)
• iso7816 (reset, apdu with trigger)

Remarks:

• I did not implement the stm32 module as I am not sure if it's needed/used but can do it if you feel it would be useful.
• Regarding the io, only line from d0 to d5 are supported. It seems to go up to d16 so should the CLI support all of them?