fix(history): fix pausing between back and forward

fix(history): fix pausing between back and forward

I realized calling history.forward() on Safari didn't immediately called
the popstate listener, so simply setting a variable before and after
history.back() and history.forward() wasn't enough.
It still doesn't work consistently between all browsers. eg: on Safari
calling history.back() mulitple times in a row will trigger only one
popstate listener but on Firefox, it will trigger as many as necessary