5 now allows you to pause current execution.
Improve error reporting on ESP32S2

2. Delay and don't clear halt request when unbricking.

also check if the target is connected, instead of reading nonsense in the void
and cherry on top, check for -h flag at the top to avoid plugging something to get help

Signed-off-by: bmx <none>

 * Add extra wait when flashing.

 * In unbrick mode, revert previous change that left the processor hanging.

Make minichlink able to be usd as a library + let it read/write debug registers on the device directly from command-line.

 * Document _write

Add ability to use vendor commands with programmers.