Video page 'video size' optional property bugs

[FayCross]

Moving these from issue 1074 as the main issue that dealt with has been resolved. The Video Size optional property on the Video page has the following bugs:

• [x] MP4 as source - doesn't fix size of video: https://xot310beta.dlearning.nl/play.php?template_id=88#page1
• [x] YouTube & Vimeo as source - fixes size of video correctly but panel is too big: https://xot310beta.dlearning.nl/play.php?template_id=88#page2
• [x] Other embed code as source (Kaltura in example) - doesn't fix size of video (this also didn't work on v3.10 though): https://xot310beta.dlearning.nl/play.php?template_id=88#page3