refactor(statesync): implement statesync peer manager

[shotonoff]

Issue being fixed or feature implemented

This is PR is related to the task TD-162:

Each module that communicates with p2p peers has its own simple peer manager implementation. Usually the code is placed into a reactor. As a result of the refactoring, peer management has been moved out of the reactor and into a separate component.
The component must listen to peer up and down events and register the peer into the peer store or remove it.

What was done?

• Migrate p2p statesync channel descriptors in p2p module
• Declare SnapshotClient interface and implement it
• Implement peer-manager component and peer-update subscriber
• Additionally create LightBlockRepository

How Has This Been Tested?

Add a couple unit-tests

Breaking Changes

N/A

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[lklimek]

PR title is confusing, we already have peer manager implemented in p2p

[shotonoff]

PR is ready to new round review

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.