Add pagination in Download section

[gouri-panda]

Is your feature request related to a problem? Please describe.
Now all the zim files are downloading at once, which may be what the user wants or not. Pagination will load and display small chunks of data at a time(i.e zim files). Loading partial data on-demand reduces the usage of network bandwidth and system resources.

Describe the solution you'd like
Add pagination and show a small chunk of data at a time. After the user goes to the end or nearly end we will ask another chunk of data to load. This will dramatically decrease the user's bandwidth and loading time.

Describe alternatives you've considered
Nothing yet.

[s-ayush2903]

Dupe of #683, see #1203 for more info. Closing

[gouri-panda]

I thought pagination will solve this problem untill OPDS came. We just have to refactor some code a little bit.