Schema Grouping

It would be a great enhancement if it is possible to create groups/collections of schemas.
This would avoid name conflicts between different schemas from different standards and allows an user to directly associate a schema with a standard by looking at the schema url.

Example:
http://example.org/api/v1/schemas/{collection}/{id}

```json
{
"$schema": "http://json-schema.org/draft-07/schema",
"$id": "http://example.org/api/v1/schemas/iec61850/DPVM",
"title": "DPVM",
"...": "..."
}
```

No files or tests are named. Start by reading the repository's schema registry and REST API entry points, then trace how schema URLs and identifiers are currently handled. Done should include a defined way to create and address schema collections so standards can be represented in URLs without name conflicts.

Written by the indexing model from the issue text.