Upgrade to binary protocol v2.0

[ifiokjr]

Description

Currently, edgedb-protocol uses the binary protocol 1.0.

For my current project edgedb_codegen I would like access to the enum name for autogenerating shared types and better type checking.

This is available in the binary protocol version 2.0: https://docs.edgedb.com/database/reference/protocol/typedesc.

This can either be as a breaking release or adding the ability to support both protocol versions.