[WebNN EP] Add quantize Ops (#18011)
### Description
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Add four quantize Ops: MatmulInteger, ConvInteger, DynamicQuantizeLinear
and DequantizeLinear.
Add datatype TensorProto_DataType_INT8 and TensorProto_DataType_UINT8.
### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
Support quantized models.
