Split PeerManager into Reusable Components

[diegomrsantos]

Description

The PeerManager currently acts as a monolithic component in the codebase, combining multiple concerns such as peer connectivity, scoring, heartbeat logic, and subnet management. This structure has led to tightly coupled logic, making it harder to reuse specific functionality in other projects, such as the Anchor Project.

The primary goal of this refactor is to split the PeerManager into smaller, reusable components that can be composed to achieve the same functionality. By modularizing the code, the functionality of the PeerManager will not only remain intact but also become easier to maintain, test, and extend. Additionally, this will allow the Anchor Project and other projects to leverage specific peer management features without needing to import or modify the entire PeerManager.