JS SDK 3.0

[RBYGLLS]

As part of the node 2.0 work, many types upon which the client depends have been moved to casper-types from casper-node, meaning these no longer need to be duplicated in the client library.

One point to note is that validation of a get-block response has been disabled. There will likely be a further change made in casper-types which will allow the JsonBlock type to be removed in favour of the actual Block type, and Block provides a public verify() method which will be suitable for this use case. Rather than spending time refactoring the validation logic, I have left it commented out in anticipation of it being replaced soon.

A final point to note is that the casper-types dependency has a patch specified in the manifest of casper-types = { git = "https://github.com/Fraser999/casper-node", branch = "2124-use-execution-journal" }. Once the node PR using this fork and branch merges, we should update the patch to casper-types = { git = "https://github.com/casper-network/casper-node", branch = "feat-2.0" }.

[hoffmannjan]

Edited the title, technically its 3.0 for js-sdk