patch for very large sliders using virtual slides

[dylan1951]

Rudimentary patch for issue #6530

Patched it enough for my purposes but unlikely to be best practices and won't cover all usages. I'm new to web dev and open source so feedback is welcome.

[nolimits4web]

Hi! Thanks! I think this line:

const adjustment = Math.trunc(swiper.translate / swiper.support.maxPx) * swiper.support.maxPx;

should be a swiper instance method as it is the same everywhere

plus maxPx shouldn't be a part of support, it is just a constant which should be inside of that adjustment calc method

[dylan1951]

OK thanks I put it into a swiper method, also tested with RTL and vertical direction.

[nolimits4web]

Merged, thank you!