So what I am searching for is a module that gives us the exactly same functionality that we already have with the image tool in Drupal 8 in the WYSIWYG editor. And that should be working with just uploaded videos. I found that this module should be doing it for D7 - https://www.drupal.org/project/video
And also this module https://www.drupal.org/project/video_embed_field is doing it for D8, but only for videos from per say YouTube, Vimeo etc.
So please let me know if you found a way to add a similar to the image (see attached screenshot) but for video
Cheers and thanks in advance!