Make empty CQ init faster in case of clean shutdown (backport #13856)

[mergify]

Proposed Changes

At CQ startup variable_queue went through each seqid from 0 to next_seq_id looking for the first message even if there were no messages in the queue (no segment files).

In case of a clean shutdown the value next_seq_id is stored in recovery terms. This value can be utilized by the queue index to provide better seqid bounds in absence of segment files.

Before this patch starting an empty classic queue with next_seq_id = 100_000_000 used to take about 26 seconds. With this patch it takes less than 1ms.

Fixes the empty classic queue part of #12848

Types of Changes

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• Bug fix (non-breaking change which fixes issue [Questions] Classic queue conversion takes very long time after upgrade to 4.0 #12848)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• Documentation improvements (corrections, new content, etc)
• Cosmetic change (whitespace, formatting, etc)
• Build system and/or CI

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Further Comments

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This is an automatic backport of pull request #13856 done by [Mergify](https://mergify.com).