Run everything through a common callback 'variant', don't separate bound
std::function and function pointers. Remeber original argument as part
of the ticker.

Because SDK does not support durations longer than ~6700seconds,
split those into multiple ticks. By default, simply divide by 2
until we reach some reasonable duration and use repeating timer
internally.

(both cases save original repeat value)

easier to implement than explaining =default failing the compilation.
and it also did not make sense to copy at all, ETSTimer is unique and
copy with an active timer will reference will still use the old instance