feat torch frontends: adding a few missing frontends to the torch.Ten…

…sor class.

ivy/functional/frontends/torch/tensor.py

@@ -119,6 +119,10 @@ def get_device(self):
         else:
             return int(self.device.split(":")[-1])
 
+    @property
+    def itemsize(self):
+        return self.element_size()
+
     # Setters #
     # --------#
 
@@ -721,6 +725,12 @@ def detach_(self):
         self.ivy_array = ivy.inplace_update(self.ivy_array, ret.ivy_array)
         return self
 
+    def cpu(self):
+        return ivy.to_device(self.ivy_array, "cpu")
+
+    def cuda(self):
+        return ivy.to_device(self.ivy_array, "gpu:0")
+
     @with_unsupported_dtypes({"2.2 and below": ("uint16",)}, "torch")
     @numpy_to_torch_style_args
     def unsqueeze(self, dim):
@@ -1543,6 +1553,10 @@ def item(self):
                 "only one element tensors can be converted to Python scalars"
             )
 
+    def element_size(self):
+        dtype = ivy.dtype(self.ivy_array)
+        return int(ivy.dtype_bits(dtype) // 8)
+
     @numpy_to_torch_style_args
     @with_unsupported_dtypes({"2.2 and below": ("float16",)}, "torch")
     def cumprod(self, dim, dtype=None):