Add an option to view the file content in the admin dashboard

[RsbhThakur]

PR #175 implemented the feature to view courses in the admin dashboard. The approve/reject admin flow for non-BR uploads. But currently the problem is that we cannot view the file contents/ open or download the files from the admin dashboard, rather we can just see the file name and approve or deny. Without seeing the actual file contents there is no use of seeing just the filenames to approve/reject files, as we cant know whats inside them. So, rather we should add an option to view/download the files from admin dashboard courses page too.

Stakeholders: @DreamBot706

[DreamBot706]

easiest solution is to just probably redirect to wherever the main site redirects on clicking the file