release-22.2: sqlstats: add limit to flush data

[blathers-crl]

Backport 1/1 commits from #97123 on behalf of @maryliag.

/cc @cockroachdb/release

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Previously, we would always let data get flushed to system tables, then the cleanup job would remove the excess data.
When the cleanup job have hiccups and get stuck data was still continuously being added, making the situation worst and requiring reset of stats in some cases.

To prevent this cases, this commit is adding a limit of how much excess data can be flushed, this way if the cleanup job stops working, the data won't blow up.

Part Of #97074

Follow up work can do a better job at cleaning the data during the flush, but this commit focus on adding the safety so it can be backported.

Release note (sql change): Add a hard limit of how much data can be flushed to system tables for sql stats.

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Release justification:

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Patches should only be created for serious issues or test-only changes.
• Patches should not break backwards-compatibility.
• Patches should change as little code as possible.
• Patches should not change on-disk formats or node communication protocols.
• Patches should not add new functionality.
• Patches must not add, edit, or otherwise modify cluster versions; or add version gates.

If some of the basic criteria cannot be satisfied, ensure that the exceptional criteria are satisfied within.

• There is a high priority need for the functionality that cannot wait until the next release and is difficult to address in another way.
• The new functionality is additive-only and only runs for clusters which have specifically “opted in” to it (e.g. by a cluster setting).
• New code is protected by a conditional check that is trivial to verify and ensures that it only runs for opt-in clusters.
• The PM and TL on the team that owns the changed code have signed off that the change obeys the above rules.

Add a brief release justification to the body of your PR to justify this backport.

Some other things to consider:

• What did we do to ensure that a user that doesn’t know & care about this backport, has no idea that it happened?
• Will this work in a cluster of mixed patch versions? Did we test that?
• If a user upgrades a patch version, uses this feature, and then downgrades, what happens?

[cockroach-teamcity]

This change is