Migrate to self-maintained generator

Full Changelog: v1.18.1...v1.18.2

Remove uncompilable code

Full Changelog: v1.18.0...v1.18.1

First release

As this repository contains code generated from 5GC specifications version must follow this format : v1.Rel.WorkflowNumber.

Rel : 5GC release used to generate the specifications.
WorkflowNumber : The workflow that has generate this code in order to easily refer to it.

NB: 0 means that it comes from no workflow and has been pushed as the initial commit of this repository. In future, a version will never end with a "0".

Full Changelog: https://github.com/5GCoreNet/openapi/commits/v18.0