emulation on host: minor updates

[d-a-v]

• Merge MockDigital.cpp and HostWiring.cpp
  one is used for CI, the other for emulation on host
• other minor fixes

[mcspr]

Formatting broke somewhere? Some things are tabs, some are 2sp, some are 4sp.
Just to avoid another extern, can't it install a certain func that either does nothing or prints things?
i.e. mock_verbose_func(nullptr) (or, [](const char*, ...) {}) to disable log, mock_verbose_func([](const char* fmt, ...) { ... do stuff ... }); to enable

[d-a-v]

Formatting broke somewhere? Some things are tabs, some are 2sp, some are 4sp.

#8455#8464 will fix this.