fix(vg-scrub-bar): Scrub bar was glitching on mobile

[KyleSmith0905]

Description

In response to my issue #101, the scrub bar was unreliable on iOS when lifting your finger. I fixed the scrub bar in probably the most low effort solution I could come up with. I tested it on iOS Chrome, iOS Safari, and Windows Chrome.

I fixed it by: Removed the scrub bar changes from happening on touchend event.

Since there are events for touchstart and touchmove, having a touchend event that also makes changes to the scrub bar percent is not needed.

Checklist

Please, check that you have been followed next steps:

• I've read the (contributing)[https://github.com/videogular/ngx-videogular/blob/master/CONTRIBUTING.md] guidelines
• Code compiles correctly (run npm start)
• Created tests (if necessary)
• All tests passing (run npm test)
• Extended the README / documentation (if necessary)

Note: I didn't run npm run commit. Also I had to remove a test, however this is just a simple result of the changes made and not an error.

[IxquitilisSaid]

LGTM! Thanks for the PR, will publish it in tandem with the v14 update.