Adds max duration check. In case it is over SDK limit, enable 'repeat'ing timer with a duration proportional to the original one and count until it executes N times, only then run the callback.Code with durations less than that executes as usual. Original proposal was to not create anything or create some kind of error state... which seems counter-productive to not help out with this pretty solvable use-case.Additional updates, while refactoring the class- Stronger types for internal time management using `std::chrono::duration`. Works the same, `std::chrono::duration` handles seconds <-> milliseconds conversion, and we don't have to remember the time type in each method. (...and even allow `once()` and `attach` as overloads instead of the current `_ms`-suffix, in a future update)- `::detach()` when timer finishes. Fixes (unintentional?) side-effect that we remain `::active()`. Plus, this destroys any lambda-bound variables that will persist with the Ticker object. And, since we can't re-arm with the existing function (`Ticker::attach_ms(uint32_t just_the_time)` and etc.)- `std::variant` aka union for internal callback storage (kind-of similar toesp8266#6918). Instead of having two separate code paths, **always** attach our static function and dispatch using type info. Also helps with the issue described above, since it will call `std::function` dtor when ptr + arg is attached instead of doing nothing.- smarter copy and move, detaching existing timer on assignment and detaching the moved-in timer object in both ctor and assignment. Copying or moving a running timer no longer blindly copies `_timer` pointer, allowing to disarm the original one. Since we are a simple wrapper around `os_timer_t`, just do the simpler thing (and not re-schedule the callback, try to store original times, etc. polledTimeout already does it and is copyable)