add swiper if elementor is not present but skeleton slider is loaded by shortcode

[Praesidiarius]

Bug Report

Q	A
Version(s)	1.0.0

Summary

If you enable shortcodes and use the skeleton slider widget, it will not work because
swiper may not be present. it is usally loaded by elementor (since 2.7.x). we should
check if elementor is present and if not, but the widget is loaded, we should check
if swiper is loaded by any other plugin and if not, enqueue swiper cdn js.

Current behavior

swiper js is not loaded by our plugin at all. we just assume its there.

How to reproduce

Use the skeleton slider with shortcode and disable elementor integration

Expected behavior

skeleton slider should always work, regardless if it is used as shortcode, elementor
widget or gutenberg block