* new network map object for network map, and verify signature and root in Signed network map and node info
* fixup after rebase
* * added certificate and key to network map server
* move DigitalSignature.WithCert back to NetworkMap.kt, as its breaking API test, will raise another PR to move it back.
* Make DigitalSignature.WithCert not extend WithKey, as per PR discussion.
* various fixes after rebase.
* move Network map back to core/node, as its breaking API test
* revert unintended changes
* move network map objects to node-api
network-parameters file read in by the node at startup, of which only the list of notaries is used. For now, the driver and MockNetwork have been updated to require notaries to be started first. This is so that the same set of network parameters can be defined for all the nodes.
CN in the legal name is not longer disallowed since it's no longer reserved for distributed notary names.
Single-node notaries now only have one identity, their main identity. Nodes part of a cluster continue to have two.
(Based off Kasia's work)
