[P2P] Define outstanding parameters & reasonable defaults

[bryanchriswhite]

Objective

Support configuration of any new degrees of freedom introduced by or since libp2p integration.

Origin Document

Out of scope for #553.

Goals

• Address outstanding // TECHDEBT in the P2P regarding values which should be parameterized
• Determine what "reasonable" defaults are for each

Deliverable

• [ ] Add missing P2P config fields
• [ ] Ensure defaults are defined in runtime/defaults/defaults.go

Non-goals / Non-deliverables

• Addressing additional // TECHDEBT comments or refactoring outside the scope of updating the P2P config

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

• [ ] Task specific tests or benchmarks: Tests should exercise new config fields
• [ ] All tests: make test_all
• [ ] LocalNet: verify a LocalNet is still functioning correctly by following the instructions at docs/development/README.md

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Creator: @bryanchriswhite

[Olshansk]

@bryanchriswhite I added the core starter task label to this since it's not something we need to do immediately, but could be a great first task to future team members.