release-24.1: allocatorimpl: include full store count in allocator error

[blathers-crl[bot]]

Backport 1/1 commits from #124073 on behalf of @kvoli.

/cc @cockroachdb/release

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An allocator error is returned when a new or replacement replica cannot be allocated to a store. The error details how many live stores there are and how many hold existing replicas along with constraints. The error makes determining the cause of up-replication stalls easier.

Also include the number of alive stores which are ineligible due to full disks in the error. The updated error message when at least one store is full:

0 of N live stores are able to take a new replica for the range (X full disk, ...)

Where N is the number of live stores, of which X have a full disk.

Resolves: #118313 Release note: None

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Release justification: Support related issue adding observability without any functionality changes.

[blathers-crl[bot]]

Thanks for opening a backport.

Please check the backport criteria before merging:

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[cockroach-teamcity]

This change is 

[kvoli]

TYFTR

The extended failure(s) are unrelated, probably pre-emption.