Add function to check if nodes are reachable via bolt

[bastelfreak]

At the moment the plans assume that all nodes are available. I had a few customer setups where one of the compilers wasn't reachable during a convert/upgrade. To not put the PE infra into an undefined state, it makes sense to check the availability before running the plans.

Summary

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Additional Context

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Related Issues (if any)

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Checklist

• [ ] 🟢 Spec tests.
• [ ] 🟢 Acceptance tests.

Changes include test coverage?

• [ ] Yes
• [ ] Not needed

Have you updated the documentation?

• [ ] Yes, I've updated the appropriate docs
• [ ] Not needed

[Jo-Lillie]

Hey @bastelfreak just wondering if you got a chance to check out the comments I left? Thanks 😃

[CoMfUcIoS]

Hey @bastelfreak this PR is stall, can you please follow up with all comments?