Add weightless hyper-connection fusion operators (#32687)
### Description
Adds four `com.microsoft` operators for weightless hyper-connections:
- `BranchwiseRMSNorm`
- `ScaledSiLU`
- `HyperConnectionPreMix`
- `HyperConnectionPostMix`
Key changes:
- Adds schemas, CPU/CUDA/WebGPU registrations, and per-operator source
files.
- Reuses existing SimplifiedLayerNormalization implementations for
compatible `BranchwiseRMSNorm` paths.
- Retains targeted fallbacks for optional, mixed-type, and
branch-specific scales.
- Adds dedicated symbolic shape-inference handlers for each operator.
- Adds operator coverage and generated documentation.
### Motivation and Context
Provides portable fused primitives for weightless hyper-connection
models while sharing established normalization infrastructure where
semantics permit. Dedicated schemas and shape-inference handlers
preserve each operator’s distinct contract without coupling them to
unrelated operators.
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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: kunal-vaishnavi <115581922+kunal-vaishnavi@users.noreply.github.com>
Co-authored-by: Kunal Vaishnavi <kvaishnavi@microsoft.com>
