pageserver: mention key in walredo errors

[jcsp]

Problem

• Walredo errors, e.g. during image creation, mention the LSN affected but not the key.

Summary of changes

• Add key to "error applying ... WAL records" log message

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[github-actions]

2460 tests run: 2337 passed, 0 failed, 123 skipped (full report)

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Flaky tests (4)

Postgres 16

• test_vm_bit_clear_on_heap_lock: debug

Postgres 14

• test_wal_page_boundary_start: release
• test_neon_superuser: debug
• test_empty_tenant_size: release

Code coverage* (full report)

• functions: 28.8% (6932 of 24085 functions)
• lines: 47.4% (42558 of 89856 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
0751821 at 2024-03-04T09:10:38.249Z :recycle:}

[koivunej]

I'd personally enjoy the key in this context. From the spans created by page_service and the output of walredo we already have the postgres "format", this would remove another step in debugging.

Checked that the Key has a good Display.