Append some APIs for Managing Trusted peers

[SimonSMH1015]

Description

Lighthouse may have some apis for managing trusted peers, like dynamic adding trusted peers; deleting trusted peers and listing trusted peers.

This is useful, especially after having
Maintain trusted peers
Add a flag to disable peer scoring

Currently we could establish a stable connection bewtween A and B, two nodes, where both of them consider other as 'trusted peer'. But If node C wants to join them, A and B should modify their lauch flags and restart. In some situaction, e.g. staking, it is not a good idea to restart nodes very often. Moreover, node wont pruning a trusted peer, even if it is offline forever. The only way now to drop that trusted peer is to restart node .

Version

Lighthouse 4.3.0

Present Behaviour

Have to resrat the client if we want to update trusted peer infos

Expected Behaviour

Have some Lighthouse APIs for updating trusted peer information
For example, /lighthouse/addTrustedpeer; /lighthouse/deleteTrustedpeer; /lighthouse/trustedPeers