Split core into more granular modules: config

[codeboten]

No description provided.

[codeboten]

For the config, i think it makes sense for each directory under config (ie. configgrpc, confighttp) to be separate modules. I'll open a few PRs for separate modules and if there's any feedback against this, we can always go w/ the full config module, but if possible i'd rather keep each package small. The only shared code i've come across thus far has been the warning method in config/internal, but for now I propose duplicating the code in the two places using it since it's pretty minimal code

[mx-psi]

From private convo, we can avoid duplicating code by using a module that has internal in its path, like opentelemetry-go does here: https://github.com/open-telemetry/opentelemetry-go/blob/b757c7083baeece1be36caa4b1c102a3ddcdfa4b/exporters/otlp/otlpmetric/go.mod#L9

[codeboten]

Closed the wrong issue by accident