Add modal to get limit input for generate csv

[Anupama1912]

Currently, in the api route, generate-csv limits the documents returned by a fixed limit (200 rn) if a limit is not specified in the query.
Add a modal which asks for a limit when the button is clicked, and pass it in as a query parameter to the route. The values should be able to be custom set by the user or automatically set as the total num of applications.