Create a PolykeyEnterprise identity provider to Polykey

[tegefaulkes]

Specification

Along with developing https://github.com/MatrixAI/Polykey-Enterprise/issues/65 we need to add PolykeyEnterprise as an identity provider plugin into Polykey. This will need to implement all the usual features such as creating and publishing an identity claim. And getting claim information for discovery and verification.

PKE will need some way to tell what node it's talking to. The communication will be over a secure web-socket so we just need to use the nodes certificate when connecting and the the PKE side should be able to verify and extract the Node's ID from the connection.

Additional context

• Related: https://github.com/MatrixAI/Polykey-Enterprise/issues/65

Tasks

1. Create an PolykeyEnterprise identity provider.
2. Support creating claims via the RPC.
3. Support TLS verification of the nodes NodeId so PKE can tell who it's talking to.

[linear]

ENG-442 Create a `PolykeyEnterprise` identity provider to `Polykey`