test(bottom-most-compaction): wal apply order

[skyzh]

Problem

A follow-up on #8103. Current main branch fails with:

assertion `left == right` failed
  left: b"value 3@0x10@0x30@0x28@0x40"
 right: b"value 3@0x10@0x28@0x30@0x40"

will be fixed after #8103 gets merged.

Summary of changes

Add multiple WALs below GC horizon above base image for key 3

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]

2910 tests run: 2794 passed, 0 failed, 116 skipped (full report)

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Code coverage* (full report)

• functions: 32.8% (6891 of 21016 functions)
• lines: 50.3% (53895 of 107181 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
792183a at 2024-06-26T01:07:22.145Z :recycle:}