release-23.2: storage: assert local single delete safety

[blathers-crl]

Backport 2/2 commits from #114820 on behalf of @jbowens.

/cc @cockroachdb/release

---

During intent resolution, examine internal keys when intending to delete an
intent using a single delete tombstone to validate that it is indeed safe
within the local Engine. This is a safety measure to validate that we do not
violate the invariants that make singe deletion deterministic and cause replica
divergence. False negatives are possible, since this safety mechanism only
examines the local engine state and only the state visible to the open lock
table iterator at the time of proposal evaluation.

Release note: none
Epic: none
Informs #114492.
Informs #114421.

---

Release justification: Adds assertions that protect and identify corruption.

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Backports should only be created for serious
  issues or test-only changes.
• Backports should not break backwards-compatibility.
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  here).
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If your backport adds new functionality, please ensure that the following additional criteria are satisfied:

• There is a high priority need for the functionality that cannot wait until the next release and is difficult to address in another way.
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Also, please add a brief release justification to the body of your PR to justify this
backport.

[blathers-crl]

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}

[cockroach-teamcity]

This change is 

[itsbilal]

LGTM

[nicktrav]

EM LGTM ✅

[nvanbenschoten]

LGTM