Chain Selection Subsystem

## Issue summary

- This subsystem implements the necessary metadata for the implementation of the [chain selection](https://paritytech.github.io/polkadot-sdk/book/protocol-chain-selection.html) portion of the protocol.
- This subsystem is a utility subsystem. So it is an implementation detail. Additional research is required to make a decision about whether we need it or we can have this code as part of some other subsystem.

## Other information and links

- https://paritytech.github.io/polkadot-sdk/book/node/utility/chain-selection.html
- https://paritytech.github.io/polkadot-sdk/book/protocol-chain-selection.html