Implement setMinPINLength command and minPinLength extension

[robin-nitrokey]

This is cherry-picked from #54.

To do:

• Fix size for data in authenticator_config
• Handle new_value === self.min_pin_length() correctly in PersistentState::set_min_pin_length (no error, but also no unnecessary write)
• Handle forceChangePin in config_set_min_pin_length
• Don’t reset force_pin_change in PersistentState::set_pin if the hash has not changed
• Fix PIN length check #43
• Rename authenticator_config to config ctap-types#79
• Add tests

To decide:

• Should we store the PIN length?

cc @0x0ece