cli/zip: Use "cluster" to identify the logical cluster instead of "tenant"

[knz]

Informs #106068.
Epic: CRDB-29380

Requested by Abbey Russell in replacement of #106117.

Release note (cluster virtualization): This patch renames the
subdirectory inside the output of cockroach debug zip when pointed
to a cluster with virtualization enabled to be cluster, which brings
the UX in coherence with the parameter of the same name in cockroach sql and the HTTP API parameter in the same name.

[cockroach-teamcity]

This change is 

[yuzefovich]

Reviewed 2 of 2 files at r1, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @knz and @Santamaura)

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-- commits line 5 at r1:
nit: maybe s/generated zip/debug zip/ for clarity?

[knz]

nit: maybe s/generated zip/debug zip/ for clarity?

Done

[knz]

bors r=yuzefovich

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)

[blathers-crl]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

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error creating merge commit from 61cee9a to blathers/backport-release-23.1-106298: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 23.1.x failed. See errors above.

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