[Feature Request] Refactor package for dedicated DR Evaluatioin

[kevin931]

What do we need?

This package, to be honest, is a bit of a behemoth with an integrated pipeline for running and evaluating DR. The latter is much more applicable in many other situations than it seems. I think we should have a dedicated package to handle DR evaluation with a standard interface, and the CytofDR.evaluation model can be a wrapper with additional methods if necessary.

The Reasons

• It's kinda hard to install the dependency trees of CytofDR with so many DR methods
• DR evaluation goes beyond CyTOF. This can be done for sources like scRNA-seq or even other domains. Multimodal methods can also benefit from this. It'll be silly to use CytofDR to evaluate DR for scRNA-seq.
• A standalone package will be easier to expand and manage, whereas CytofDR is more or less stable as of now.

What's required?

We need to flesh out the new interface, but other than that, a simple package won't be too hard.