Refactor the network tests

[zivkovicmilos]

Description

This PR refactors the tests in the networking package, fixes bugs and adds new coverage tests.

Additionally, this PR resolves all pending linting errors (3937fbc) and modifies the GH Actions workflow file for the linter (886c4d5)

Encountered issues:

• Servers were using taken ports in concurrent environments in tests
• Invalid event waits within tests
• Low timeouts set for test completion, causing tests to fail even though they succeeded

Failed linting

Currently, the linting checks fail on GH actions because some structures are unused due to test skips.
This PR should wait for #312, which contains the libp2p package updates before unskipping the tests and fixing linting errors that arise from this.

Changes include

• Bugfix (non-breaking change that solves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have tested this code
• I have updated the README and other relevant documents (guides...)
• I have added sufficient documentation both in code, as well as in the READMEs

Additional comments

Due to a known and fixed libp2p bug (libp2p/go-libp2p#1090), some test have been skipped for now:

• TestSimpleGossip
• TestSyncer_PeerDisconnected

The Polygon SDK is running version v0.12.0 of libp2p, where this issue is still present.

These tests will be un-skipped as soon as #312 is merged (after the libp2p package is updated to v0.14.0

EDIT: Tests un-skipped ✅

[brkomir]

Overall looks ok! Fix the linter errors and we are good to go

[Kourin1996]

Looks good!

[lazartravica]

Flawless, great job.

Good thinking about the helper methods for bootstrapping the network.