Fuse Pad even if Cast is present in-between (#21640)
### Description
This change enhances the existing Pad Fusion to fuse Pad even if a Cast
operator is present between Pad and Conv/MaxPool/AveragePool. It keeps
the Cast as it is.
<pre>
/*
* Before Fusion:
* Pad
* |
* Cast (Optional)
* |
* Conv/MaxPool/AveragePool
*
* After Fusion:
* Cast (Optional)
* |
* Conv/MaxPool/AveragePool
*/
</pre>
### Motivation and Context
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- If it fixes an open issue, please link to the issue here. -->