API BREAKING CHANGE: Remove back-compat interface shims

[DaveTryon]

We added the IConfiguration2 and ILicenseInformationFetcher2 interfaces to maintain backward compatibility with the 3.0 API interface. Since the 4.0 API interface is a breaking change, we can remove the 2 shim interfaces for simplicity.

[DaveTryon]

/azp run

[github-actions]

This PR changes files in the API project. Does it change any of the API interfaces in any way? Please note that this includes the following types of changes:

• Changing the signature of an existing interface method
• Adding a new method to an existing interface
• Adding a required data member to a class that an existing interface method consumes

Because any of these changes can potentially break a downstream consumer with customized interface implementations, these changes need to be treated as breaking changes. Please do one of the following:

Option 1 - Publish this as a breaking change

1. Update the documentation to show the new functionality
2. Bump the major version in the next release
3. Be sure to highlight the breaking changes in the release notes

Option 2 - Refactor the changes to be non-breaking

1. Review this commit, which adds a new interface in a backward-compatible way
2. Refactor the change to follow this pattern so that existing interfaces are left completely intact
3. Bump the minor version in the next release

[DaveTryon]

/azp run

[sfoslund]

Love being able to delete all this code!