Video duration added on thumbnail (as seen in youtube)

[mvp5464]

PR Fixes:

• 1 Added the total video duration on the thumbnail
• So that Just to check video duration we don't need to start every video (or check mobile app for)

Resolves #329

Checklist before requesting a review

• [x] I have performed a self-review of my code

• [x] I assure there is no similar/duplicate pull request regarding same issue

• Added duration

[mvp5464]

Sir, Is it good or should I improve the duration UI, or any other changes from your side.

[hkirat]

/bounty $25