5149: Implement Chalk variable kinds r=flodiebold a=flodiebold
This means we need to keep track of the kinds (general/int/float) of variables in `Canonical`, which requires some more ceremony. (It also exposes some places where we're not really dealing with canonicalization correctly -- another thing to be cleaned up when we switch to using Chalk's types directly.)
Should fix the last remaining issue of #2534.
Co-authored-by: Florian Diebold <florian.diebold@freiheit.com>
a33eefa3b2