Split core into more granular modules: confmap

[evan-bradley]

Is your feature request related to a problem? Please describe.

In order to use providers and converters individually, they need to be split into their own modules. This is required for #4759.

Describe the solution you'd like

Split each provider and converter currently in the confmap into its own module, keeping the current directory structure.

Describe alternatives you've considered

We could change the directory structure when moving these into their own modules.

Additional context

Relates to #7054

cc @mx-psi