[QNN EP] Add FusedMatMul operator support (#27044)
### Description
Add support for the FusedMatMul operator in the QNN execution provider.
FusedMatMul is a contrib operator in the Microsoft domain that performs
a fused matrix multiplication with optional bias addition and
activation.
Implementation details:
- Added FusedMatMulOpBuilder class that decomposes FusedMatMul into:
1. MatMul operation
2. Optional bias addition
3. Optional activation (Relu, Sigmoid, Tanh, Gelu)
- Handles various attributes: transA, transB, alpha, and activation
- Supports higher rank tensors and different data types
Added comprehensive tests:
- Basic functionality tests with various configurations
- Tests for both CPU and HTP backends
- QDQ (Quantize-Dequantize) tests for 8-bit and 16-bit precision
### Motivation and Context
Since QNN HTP doesn't support, decomposing it into QNN HTP supported
operators to improve the inference time of customer models having
FusedMatMul operator.
