🦫 Add Golang target schema generation

[bdeneux]

As part of our ongoing efforts to improve and expand our build process, I propose the addition of a Golang target for schema generation. This will allow generate Golang types from our contract schemas, further enhancing the versatility and utility of our build process.

The introduction of this feature is crucial for the future Axone Go SDK. Having the contract types available in Go will facilitate communication with the contract and ensure proper lifecycle process versioning and more.