Dedupe RegistryHost configuration types

[turan18]

Description

Right now, we have two separate constructs in our config for providing registry specific configurations: ResolverConfig and Registry. The Registry config struct has been ported over from containerd/CRI. Containerd plans to move away from defining registry configurations directly in the config.toml and instead have users create host configuration files separately and provide the path to those configurations via the ConfigPath field. We should figure out a way to de-duplicate these constructs so that we have a centralized way of setting registry configurations.

Steps to reproduce the bug

No response

Describe the results you expected

1. (Preferred - Backwards Incompatible) Remove the CRI Registry struct and all other containerd specific fields from ResolverConfig and replace it with a ConfigPath field. Rename ResolverConfig to RegistryConfig.

2. Same as 1, but keep name as is ResolverConfig.

3. Remove our Registry config, import the Registry config type from containerd and merge it with ResolverConfig.

Host information

1. OS:
2. Snapshotter Version:
3. Containerd Version:

Any additional context or information about the bug

No response