[P2P] Host/port shouldn't be required in client debug mode

[bryanchriswhite]

Objective

Improve user experience of the debug CLI.

Origin Document

Goals

• Debug CLI command is usable when hostname and port P2P config fields are absent or empty string

Deliverable

• Update P2P module #Create() logic to set m.listenAddrs = libp2p.NoListenAddrs if isClientDebugMode (regardless of `m.cfg.ConnectionType)
• Remove POCKET_P2P_HOSTNAME env var from cli-client.yaml manifest
• Fix resulting or related bugs and/or errors

Non-goals / Non-deliverables

• Modifying the P2P config
• Modifying Network implementations

General issue deliverables

• Update the appropriate CHANGELOG(s)
• Update any relevant local/global README(s)
• Update relevant source code tree explanations
• Add or update any relevant or supporting mermaid diagrams

Testing Methodology

TODO

• All tests: make test_all
• LocalNet: verify a LocalNet is still functioning correctly by following the instructions at docs/development/README.md
• *k8s LocalNet: verify a k8s LocalNet is still functioning correctly by following the instructions here

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