Sketch-Guided Equality Saturation

[Bastacyclop]

Uses https://github.com/elevate-lang/elevate/pull/28 comments:

• the RewriteDirected mechanism improves on previous attempts, but is still bugged (problem with e-class ids and find)
• beam extraction is implemented but lacks a way to promote diversity inside the beam
• memory is pretty printed in e.g. kibibytes, but maybe kilobytes are more familiar to read and compute with
• the separableConvolution2DRewrite test is now counting rule applications in one case, defining a special traversableCountApplications which is very redundant with other Rise traversal in Elevate.

[Bastacyclop]

Thanks for the review @michel-steuwer , I have adressed your comments.