Metadata Modules

## Feature Description
Ability to independently generate a snippet or module of metadata and commit/import into the main metadata file that generates the API. The module could be around domain modeling, authorization, transformations, allow lists and so on.

## User value / outcome
Allows for seamless collaboration within the same team and also with external team members. Your team-mates can now work inside a module without being bothered or blocked by the entire metadata. Also opens avenues to import community generated metadata and easily embed that logic in your API. In addition there will be tooling to inform you about conflicts and stitching the different metadata branches together.

## Current status (design, alpha, beta etc.)
Currently in design phase. Expected to come out in phases starting from June 2023 as part of the Beta launch

The issue names no files, tests, or entry points and is still in the design phase. Start by clarifying the module format, how modules are imported into the main metadata file, and how conflicts and stitching should work. Done would require an agreed design and implementation plan for these flows.

Written by the indexing model from the issue text.