solver: swap catas with recursion, fuse travs (#7519)

* solver: swap catas with recursion, fuse travs

* whoops

* add traverseWithKey to cabal-install-solver (#7533)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* replace sequence . mapWithKey with traverseWithKey

* more sequence -> traverse

* Update Preference.hs

fix bad merge

* Update Solver.hs

Co-authored-by: Gershom Bazerman <gershom@arista.com>
Co-authored-by: Emily Pillmore <emilypi@cohomolo.gy>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>