Fixed Mark as complete , Sidebar Mobile version

[Vijay-kumar-bantu]

PR Fixes:

• 1 Mark as complete feature is fixed and additionally course video will be marked as complete automatically when user completes the video.
• 2 Sidebar of mobile UI fixed

Siderbar Mobile Ui Before:

Siderbar Mobile Ui After:

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

[AyushShivhare79]

I had already created PR for mark as complete + some more bugs.

[hkirat]

mark as complete is fixed for now, please create new PR for rest