Upgrade "SetConfig" Command to use Core Library

[angela-young]

What does this PR do?

Rewrites the force:config:set command to use the core library instead of the CLI library. All functionality should remain the same aside from minor changes in the output displayed.

What issues does this PR fix or reference?

@W-9466545@

Functionality Before

Functionality After

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[gbockus-sf]

closing this PR for now as it'll need some touches to get it ready. We have two tickets tracking the work so I linked both to this PR for future reference.