Fix reporting of hosts in batch script runs

[sgress454]

Details

Applying the patches from
#32516 (comment) and
#32563
onto main.

This fixes:

• Batches where all remaining hosts are deleted will be correctly marked as "finished"
• Batches scheduled for the future, and then canceled, will have al hosts marked as "canceled" rather than pending

Checklist for submitter

If some of the following don't apply, delete the relevant line.

• Input data is properly validated, SELECT * is avoided, SQL injection is prevented (using placeholders for values in statements)
• If paths of existing endpoints are modified without backwards compatibility, checked the frontend/CLI for any necessary changes

Testing

• Added/updated automated tests

• Where appropriate, automated tests simulate multiple hosts and test for host isolation (updates to one hosts's records do not affect another)

• QA'd all new/changed functionality manually

  • Started a new batch script run with one host, deleted that host, and triggered the batch_activity_completion_checker schedule, and verified that the batch was moved to "finished".
  • Scheduled script
    • Created a new batch script run scheduled for a future date
    • Canceled that batch run
    • Clicked on the batch run in the "finished" tab of the batch scripts list
    • Verified that the number of canceled hosts = the number of targeted hosts for that batch, and all other numbers were 0.
    • Verified that clicking the canceled hosts number navigated to the correct list of canceled hosts
  • "Run now" script
    • Created a new batch script run with "run now"
    • Waited for at least one host to run.
    • Canceled that batch
    • Clicked on the batch run in the "finished" tab of the batch scripts list
    • Verified that the number of canceled hosts = the number that were still pending when I canceled the script, and that the # of pending hosts was 0
    • Verified that clicking the canceled hosts number navigated to the correct list of canceled hosts
  • Multiple batches with the same hosts don't bleed into each other
    • Created another batch script with the same hosts, scheduled for the future
    • Verified that the "pending" host list is correct

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 64.02%. Comparing base (27560c7) to head (5f0c963).
⚠️ Report is 31 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #32517   +/-   ##
=======================================
  Coverage   64.02%   64.02%           
=======================================
  Files        1987     1987           
  Lines      195579   195622   +43     
  Branches     6461     6543   +82     
=======================================
+ Hits       125221   125254   +33     
- Misses      60560    60565    +5     
- Partials     9798     9803    +5     

Flag	Coverage Δ
backend	65.25% <100.00%> (+<0.01%)	⬆️

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