Add the application id to the search data

This adds to the the old style search data (the new style using the search_document already has the id). This is used in the old filter interface, and is required so that searching for the id will make sure the submission shows up in the results.

If there are already submissions in the database, the following must be run from a django shell:

from hypha.apply.funds.models import submissions
[s.save() for s in submissions.ApplicationSubmission.objects.all()]

Fix ots/clients/ardc/hypha-tracker#257: Searching for application numbers yield no results (or the wrong results)