Schema to Go code generator

[ghost]

Please describe what you would like to see in this project

We need a go:generate code generator that takes an Arcaflow YAML structure loaded using this library (see schema package) and generates Go code (structs, etc) as well as the type definitions in Go code. The result should be something like this and this.

Please describe your use case

Go does not have enough information in its typing system to be able to construct an Arcaflow schema (no annotations). We need the code generator to turn the typing information into usable Go code without duplicated effort.

[josecastillolema]

Validated the skeleton of a working hardcoded setup with the arca-team.
Moving on to the actual parsing.

[josecastillolema]

Splitting the feature into two smaller PRs:

• PR#1 for the typedef file
• PR#2 for the shema file

PR#1 submitted for review.