Set local video in Stripe to 4:3 aspect-ratio

[Antreesy]

🖼️ Screenshots

🏚️ Before	🏡 After

As mentioned in corellated issue #8815 :

... Even if the camera supports a higher resolution in calls the resolution is requested to be 720x540. This is a default value chosen for performance reasons, both for CPU load when encoding the video and for network bandwidth when sending it.

Maximum capable video resolution is fixed at 4:3. This PR adjusts width and height of local video frame in stripe to fit in desired resolution and avoid its cropping

🚧 TODO

• Remove video width lock at 300px
• Set aspect-ratio to mentioned resolution at 4:3
• Code review

🏁 Checklist

• 📘 API documentation in docs/ has been updated or is not required
• 📗 User documentation in https://github.com/nextcloud/documentation/tree/master/user_manual/talk has been updated or is not required
• 🔖 Capability is added or not needed

[ShGKme]

I have this view on my local test. Is it was was expected (it is not cropped)? Shouldn't it be stretch so the video would have rounded corners?

[ShGKme]

Hmm... Now it looks ok.

[ShGKme]

Steps to reproduce:

1. Make a call from account 1 in a group chat
2. Join a call with account 2 with an enabled camera
   
3. By default, account 1 will be shown. The Video is cropped.
   
4. Leave and re-join. The video is not cropped, but also not rounded:
   
5. Switch to the grid view and back to the speaker view. Everything is ok.
   

[ShGKme]

I may admit that this may be a peculiarity of my environment... Does it work fine on yours?

[ShGKme]

The code looks fine, no cropping now. The aspect ratio is 1.33333 fallback until reconnecting and reopening the local video on my test.

I'm not sure if we want to merge it without solving #8815.

[Antreesy]

Is it what is expected in the PR?

Yes, because videostream comes with aspect-ratio: 1.33, and previous styles cutted it even more, up to 1.24.
I want to fix at least this for now, and use as a basement in following up fixes on mentioned issue.
Later we could pass a defined aspect-ratio from source with constraints, and use it as SSOT