onnxruntime

[QNN EP] Support reduce ops with axes as initializer input  (#15126)

### Description
- Adds support for newer opset of Reduction operators (ReduceSum,
ReduceMax, ReduceMin, ReduceMean, ReduceProd) with axes as an
initializer input.
- Adds tests for HTP and CPU backends.

### Motivation and Context
Newer opset versions changed the `axes` attribute into an optional
input. This PR adds support for these newer reduction operators as long
as the axes input is defined as an initializer. The goal is to enable more models on QNN.