Enhance our tests for sparse kernels (medium level, independent, starter)

Bugzilla Link	52307
Version	unspecified
OS	Linux
CC	@joker-eph

Extended Description

The sparse compiler relies on FileCheck based tests (https://github.com/llvm/llvm-project/tree/main/mlir/test/Dialect/SparseTensor) and "regression" test (https://github.com/llvm/llvm-project/tree/main/mlir/test/Integration/Dialect/SparseTensor/CPU). These tests make sure that the generated IR is as expected and that the lowering runs "end to end". Most of these tests were developed in conjunction with particular features while they were being added.

But we can always use more tests. Real-life kernels with higher dimensional tensors, tests with difficult co-iterating constructs, etc.

The entry requests researching new tests and adding them to our testing directories. This is a relatively independent starter project, since it can be done without a very deep knowledge of the sparse compiler internals (although insights in those always help, of course).