Updated peer score strategy to not fully connect

[Raynos]

This updates the peer selection score strategy to mark unconnected peers as the lowest score.

This means that we will not fully connect and will in general use 1 peer most of the time.

The only time more then 1 peer is used per sub channel:

• minConnections is configured for p2p
• hyperbahn is used and extra inbound peers are estabilished.

r: @kriskowal @prashantv @jialiehu

[CLAassistant]

All committers have signed the CLA.

[albertyfwu]

not familiar with tchannel code, but thanks for doing this