Include manifest file inside zip

[chinmoy12c]

Currently, there are as many manifest requests as there are forms downloaded. This leads to a lot of network requests for instance when there are 1000 forms. We need to devise a method to include the manifest files inside the zip itself whereby the manifest files would be pulled from the zip and if not found only then a network call would be made to download it.

One thing to pay attention to is that the manifest files are used to check for new media, a way is needed to update the manifest file when a form is updated and new media is added to the form.