Investigate using config collections

This initial "bug" report is five years too late. It is now a major feature request.

Config collections are an undocumented subsystem that was introduced after this module was written. It would be ideal if we used them, as they should allow for full schema support. Schema validation is a nicety that only matters to programmers, so far as I can tell, so it is not an essential feature.

Problems that need to be overcome in order to support this initiative are:

1. The ability to discover what config has been overridden and stored.
2. The ability to know which elements of a config object are being overridden, since we support partial overrides.
3. The ability to reliably discover configuration objects and their related forms without using a config_translation.yml style hack.
4. The ability to integrate existing or replacement functionality for a Domain Config UI as shown in https://github.com/agentrickard/domain/pull/434
5. An upgrade path for existing users.
6. Working tests

I will not be working on this without dedicated, paid support, but I am happy to review code. Pull requests are preferred for work of this complexity.

Original post:

Using config_inspector module to validate config schemas we get "No schema" for every domain config override.
According to Drupal's documentation it is recommended to have schemas for configuration objects, see https://www.drupal.org/docs/8/api/configuration-api/configuration-schema... →