[xnnpack][lite-int] Handle Constant Data (#89445)
Handling constant data for xnnpack delegation. This allows us to handle new modules like such:
```
class Module(torch.nn.Module):
def __init__(self):
super().__init__()
self._constant = torch.ones(4, 4, 4)
def forward(self, x):
return x + self._constant
```
this is the precursor work to handling convolution, as we need to serialize constant data(weights)
Differential Revision: [D41050349](https://our.internmc.facebook.com/intern/diff/D41050349/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89445
Approved by: https://github.com/digantdesai
