[MLIR][Presburger] Remove `spaceKind` from PresburgerSpace

This patch remove `spaceKind` from PresburgerSpace, making PresburgerSpace only
a space supporting relations.

Sets are still implemented in the same way, i.e. with a zero domain but instead
the asserts to check if the space is still set are added to users of
PresburgerSpace which treat it as a Set space.

Reviewed By: arjunp

Differential Revision: https://reviews.llvm.org/D121357