Teku API for managing static and direct peers

[lucassaldanha]

During the Holesky incident, one of the issues was finding (and maintaining) good peers. As other nodes were coming up online, it was helpful to add them to our list of static peers. However, we only support loading them from our config. It would be helpful to have some peer management APIs to be able to add/remove peers without restarting our node.

Extra points if we can use ENR or MultiAddr when configuring the peers.

Note: might require a change in Libp2p.

Note: maybe this should be considered a standard API.

Update: An endpoint has been created but it only accept MultiAddress as input, we could eventually add the capability of adding using ENR.

[gfukushima]

closing this ticket as the endpoint to add peer has been added in #9431. I've added some follow up tickets that would be nice to have at some point.