[FIX] website_slides: fix youtube URL params ignored

Issue

	- Install website slides
	- Create a slide with document url =
	  a youtube video URL with params like ?rel=0
	- Check it on the website with debugger

	The iframe url doesn't have ?rel=0

Cause

	We only take the video ID and pass it
	to a predefined string. We add light
	theme params too.

Solution

	Split the given url in order to
	get the params and pass it to
	the predefined string.

OPW-2275928

closes odoo/odoo#53195

Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>