Now files can also be added from topic page

Multiple files can be created from topic page , and at the same time it will get saved into the collection of that topic instance by ensuring that same files can not be uploaded in to the topic

Bugs removed for uploading files. 
previously files other than videos was giving the error while uploading. i.e it was not getting landed to the details page after saving file. Now files uploading is working properly given the conditions for saving all type of files.