perf: cap max count on list views (backport #25348)

[mergify]

Problem: In InnoDB counting is essentially O(N) operation, it can be pretty fast on indexes so it doesn't feel like it most of the time but when filters don't use any index it usually means doing a full table scan.

get_count accounts for 4% of all requests on FC - #21742 . This isn't even considering outliers that were removed from data. Users with large DB often need to disable count on list views for site to stay usable.

This makes Count sad.

Fix: Adding a limit will stop the scan as soon as that many records are matched.

Implementation:

• We only show accurate count up to 1000 values now
• User can click on the count to get an accurate count if really required. Most users don't care about this at all!

Outcome:

• If filters don't match more than 1k records then this PR makes no difference.
• If filters match more than 1k records then all that extra cost is now not paid. So for site with millions of matching records get_count will finish much faster. The main benefit is user won't NEED to disable the count.

Count is happy now.

---

This is an automatic backport of pull request #25348 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of ae649aa has failed:

On branch mergify/bp/version-14-hotfix/pr-25348
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Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   frappe/desk/reportview.py

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Cherry-pick of a49fafb has failed:

On branch mergify/bp/version-14-hotfix/pr-25348
Your branch is ahead of 'origin/version-14-hotfix' by 1 commit.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit a49fafbf8e.
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Changes to be committed:
	modified:   frappe/public/js/frappe/db.js
	modified:   frappe/public/js/frappe/list/list_view.js
	modified:   frappe/tests/test_db_query.py

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   frappe/desk/reportview.py

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[frappe-pr-bot]

🎉 This PR is included in version 14.68.0 🎉

The release is available on GitHub release

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