[MLIR] Introduce normalized single-result unbounded AffineApplyOp

Supervectorization does not plan on handling multi-result AffineMaps and
non-canonical chains of > 1 AffineApplyOp.
This CL introduces a simpler abstraction and composition of single-result
unbounded AffineApplyOp by using the existing unbound AffineMap composition.

This CL adds a simple API call and relevant tests:

```c++
OpPointer<AffineApplyOp> makeNormalizedAffineApply(
  FuncBuilder *b, Location loc, AffineMap map, ArrayRef<Value*> operands);
```

which creates a single-result unbounded AffineApplyOp.
The operands of AffineApplyOp are not themselves results of AffineApplyOp by
consrtuction.

This represent the simplest possible interface to complement the composition
of (mathematical) AffineMap, for the cases when we are interested in applying
it to Value*.

In this CL the composed AffineMap is not compressed (i.e. there exist operands
that are not part of the result). A followup commit will compress to normal
form.

The single-result unbounded AffineApplyOp abstraction will be used in a
followup CL to support the MaterializeVectors pass.

PiperOrigin-RevId: 227879021