[GSoC] - Added Multimedia support in Organization-Feed-Page

[rutvik11062000]

What kind of change does this PR introduce?

Issue Number:

Fixes #879 (7/8 TODO)

Did you add tests for your changes?
Yes updated.

Snapshots/Videos:

AutoPlayDemo.mp4

If relevant, did you update the documentation?
No.

Summary
Major Tasks:

1. Added service to show media (Photos and Videos).
2. Auto play and pause of video depends upon the widget place on screen.
3. Functionality to mute or unmute the audio of particular video.
4. Fixed post vanishing when page is refreshed.

Does this PR introduce a breaking change?
No.

Other information
Future PR will include global audio controlls.

Have you read the contributing guide?

Yes