[mlir][sparse] Cleaning up the dim/lvl distinction in SparseTensorConversion

This change cleans up the conversion pass re the "dim"-vs-"lvl" and "sizes"-vs-"shape" distinctions of the runtime. A quick synopsis includes:

* Adds new `SparseTensorStorageBase::getDimSize` method, with `sparseDimSize` wrapper in SparseTensorRuntime.h, and `genDimSizeCall` generator in SparseTensorConversion.cpp
* Changes `genLvlSizeCall` to perform no logic, just generate the function call.
* Adds `createOrFold{Dim,Lvl}Call` functions to handle the logic of replacing `gen{Dim,Lvl}SizeCall` with constants whenever possible. The `createOrFoldDimCall` function replaces the old `sizeFromPtrAtDim`.
* Adds `{get,fill}DimSizes` functions for iterating `createOrFoldDimCall` across the whole type. These functions replace the old `sizesFromPtr`.
* Adds `{get,fill}DimShape` functions for lowering a `ShapedType` into constants. These functions replace the old `sizesFromType`.
* Changes the `DimOp` rewrite to do the right thing.
* Changes the `ExpandOp` rewrite to compute the proper expansion size.

Depends On D138365

Reviewed By: aartbik

Differential Revision: https://reviews.llvm.org/D139165