adding shortcuts on the video player buttons controltext

[barisgul15]

Motivation and Context

fixes #1289

Description

• shortcuts are added to video players buttons. before: play -> after play (k)]
• keyboard shortcuts should be added to the menu under keyboard icon

Steps for Testing

1. Log in
2. Navigate to a Video
3. Check the text appears when the mouse is on one of the player buttons
4. Open menu at the home page and click keyboard icon

Screenshots

It used to say only play, not the keyboard shortcuts are also displayed.

Keyboard shortcuts in menu:

Keyboard shortcuts popup:

[github-actions]

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Logins

Kurs1	Kurs2	Kurs3	Kurs4
public	public	loggedin	enrolled
prof1	prof1	prof2	prof1 prof2
student1 student2 student3	student1 student2	student2 student3	student1 student2

[SebiWrn]

You shouldn't create js files directly but rather create Typescript files and include them into the bundles so they get optimized. Please move your js code to the correct typescript files

[SebiWrn]

If you still want to merge this PR please reopen the PR and fix the issues

[joschahenningsen]

Are we sure we want this on every page and not just on the watch page? The shortcuts are only relevant there, right?

[karjo24]

This was only a rewrite of the existing, closed PR to better fit our codebase so it can be discussed again. Having said that, I agree. The question is where to incorporate this into the watch page? I'm not too happy about any other place and the menu where it currently is incorporated isn't included in the watch page.