Backport of Add NodeMaxAllocations to client configuration into release/1.10.x

[hc-github-team-nomad-core]

Backport

This PR is auto-generated from #25785 to be assessed for backporting due to the inclusion of the label backport/1.10.x.

The below text is copied from the body of the original PR.

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Description

This PR introduces the concept of maximum allocations to the client via the client configuration file. This includes updates to the nomad node status command to add an Alloc Count column to the Allocated Resources section of the single node view. If node_max_alloc is defined it will be included as the denominator, otherwise we'll just report the count as a whole number.

Testing & Reproduction steps

The below screenshots were generated by running a single agent dev cluster and passing it the minimal configuration in command/agent/test-resources/client_with_max_allocs.hcl.

Single node status output when client.node_max_allocs is not set

Single node status output when client.node_max_allocs is set

Links

Github Issue #12783

Contributor Checklist

• Changelog Entry If this PR changes user-facing behavior, please generate and add a
  changelog entry using the make cl command.
• Testing Please add tests to cover any new functionality or to demonstrate bug fixes and
  ensure regressions will be caught.
• Documentation If the change impacts user-facing functionality such as the CLI, API, UI,
  and job configuration, please update the Nomad website documentation to reflect this. Refer to
  the website README for docs guidelines. Please also consider whether the
  change requires notes within the upgrade guide.

Reviewer Checklist

• Backport Labels Please add the correct backport labels as described by the internal
  backporting document.
• Commit Type Ensure the correct merge method is selected which should be "squash and merge"
  in the majority of situations. The main exceptions are long-lived feature branches or merges where
  history should be preserved.
• Enterprise PRs If this is an enterprise only PR, please add any required changelog entry
  within the public repository.

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Overview of commits

• 55523ec