Add network uids

[camfairchild]

This PR adds the subtensor code for accessing the chain under the new finney chain RPCs.

Implemented in this PR

netuids

• check registration on network uid
• inspect hotkey see network uid
• view network uids in overview
• register to network uid
• serve to network uid
• implement btcli full
• list all subnets and properties

delegation

• show delegates and take
• stake to delegate
• check if delegate
• become delegate

neurons

• new axon metadata
• new prometheus metdata
  • grab from neuron
  • add grab by itself
• add grab axon by itself
• add grab single neuron
• add grab rate limit
• new metagraph api subtensor.metagraph()

set weights

• set weights with version
  • grab correct version and encoding
  • set in set weights call and val