Order escalation rules by elapsed time and status

What does this MR do?

Addresses #334736 (closed) to unblock !64101 (merged) per !64101 (comment 614351408)

Sorts escalation rules by number of minutes & status. This occurs both when queried and as part of mutation response.

Changelog trailers not included as the feature is still feature flagged.

Testing

Enable :escalation_policies_mvc feature flag & navigate to Monitor > Escalation policies. Set up an on-call schedule if needed.

Viewing an escalation policy on page load or after create/update should keep the rules sorted.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

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Security

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