[Networking] Implements Pluggable Conduit Factory

[yhassanzadeh13]

This PR refactors the networking layer to decouple the creation of Conduits into a stateful ConduitFactory interface, which provides a pluggable Conduit creation functionality for the networking layer. This is a prerequisite decomposition to enable testing our nodes under Byzantine behavior through the Programmable Conduit (PC) framework (see the attached issue for more details).

In a nutshell, a Conduit is the interface that enables an engine push a message to a subset of the remote nodes through the networking layer.

[yhassanzadeh13]

May skip reviewing this file, not a new logic, just organizing into a new file.

[gomisha]

Can you comment on why the channel logic was moved into a separate file? Is it to allow test channels to be created to simulate BFT attack scenarios?

[codecov-commenter]

Codecov Report

Merging #1986 (19e3e15) into master (28d3623) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #1986      +/-   ##
==========================================
- Coverage   57.61%   57.59%   -0.02%     
==========================================
  Files         631      631              
  Lines       36172    36186      +14     
==========================================
+ Hits        20841    20842       +1     
- Misses      12710    12720      +10     
- Partials     2621     2624       +3     

Flag	Coverage Δ
unittests	57.59% <0.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
network/p2p/conduit/conduit.go	0.00% <0.00%> (ø)
network/p2p/network.go	0.00% <0.00%> (ø)
network/test/testUtil.go	93.75% <ø> (ø)
...s/hotstuff/votecollector/staking_vote_processor.go	85.96% <0.00%> (-3.51%)	⬇️
admin/command_runner.go	79.20% <0.00%> (ø)
...sus/approvals/assignment_collector_statemachine.go	50.00% <0.00%> (+2.88%)	⬆️

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