Upload video

[AMChierici]

@bordernone I tested this and

• video upload works well
• embeddings added on the fly works well
• ratings are removed correctly in the player

However, you need to fix:

• when I ask by voice, I can ask only one question, then it stops listening (but it does not show me the error message "please provide a rating")
• when I click on a suggestion card, it gives me the error message "please provide a rating" and I cannot ask anything
• when I ask by typing, it works fine without error messages.

I am wondering: would it be easy quick to make the interaction by voice like that: press space bar to speak, release space bar to stop listening. IF it's easy, please implement into this PR. If it takes longer than a day, let's keep it for the next PR.

Thanks!