Update Candidate's results report filters

[JohnMwashuma]

User story

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A user should be able to filter candidates votes results by:

• Races with ballots marked as releasable.
• Races with a user-entered/user defined % of polling stations processed.
• Include/Exclude Stations tabulated from releasable races.
• All candidates, Active or a pre-determined number of leading candidates.

In total the candidates results report will have filters in the following order:

• All/Available for release/Not available for release Ballot Status
• Races.
• User defined % of polling stations processed per Race(s) (default 0: meaning no percentage applied).
• Centers.
• Station Status
• Stations.
• All/Active/InActive Candidates.
• Pre-determined number of leading candidates (default 0: meaning no pre-determined number applied).

Task check

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• [x] Enable filtering results by station id's without the need to select other filters e.g. centers. Related to: https://github.com/onaio/tally-ho/issues/359
• [x] Create a Ballot Status filter drop down for filtering results. The options should include:
  • [x] All (All ballots)
  • [x] Available for release (ballots where the available_for_release field is true)
  • [x] Not available for release (ballots where the available_for_release field is false)
• [x] Create a Station Status filter drop down for filtering results. The options should include:
  • [x] All (All stations)
  • [x] Active (stations where the active field is true)
  • [x] In Active (stations where the active field is false)
• [x] Create an input field filter for percentage of polling stations processed per race(s) selected with a default value of 0 (0 meaning it has not been applied). When applied the following should happen:
  • [x] Updates retrieval logic for stations and centers filter options to the following:
    • Get stations assigned to the selected races, use the center field and get the respective results forms then filter by ballot race.
    • Group by station id and count the total result forms assigned, total result forms assigned and in ARCHIVE form state and station processed percentage which will be *forms in archive/total result forms 100**.
    • Filter the above results where the calculated station processed percentage is equal or greater than the user defined station processed percentage and return the station id's and center id's.
    • The actual queryset

      stations_processed_percentage = <user_input>
      qs = Station.objects.filter(
      tally__id=tally.id,
      center__resultform__ballot__race_type=RaceType.PRESIDENTIAL
      ).values('id').annotate(
      total_result_forms=Count(
      'center__resultform__barcode',
      distinct=True
      ),
      total_result_forms_archived=Count(
      'center__resultform__barcode',
      distinct=True,
      filter=Q(center__resultform__form_state=FormState.ARCHIVED)
      ),
      processed_percentage=Round(
      100 * F('total_result_forms_archived')/F('total_result_forms'),
      digits=2
      )).filter(
      processed_percentage__gte=stations_processed_percentage).values(
          'id')
      station_ids = [item.get('id') for item in qs]

• [x] Create a filter drop down for all candidates, active and inactive candidates. When applied filter the results where the Candidate model field active is set to the applied value.
• [x] Set the default value of number of leading candidates filter to 0. (0: meaning no pre-determined number applied).

Acceptance criteria

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A user should be able to filter candidates votes results by:

• [ ] Races with ballots marked as releasable.
• [ ] Races with a user-entered/user defined % of polling stations processed.
• [ ] Include/Exclude Stations tabulated from releasable races.
• [ ] All candidates, Active or a pre-determined number of leading candidates.