full: improve error handling and error messages.

[ysiraichi]

This PR refactors the tensor_methods::full and tensor_methods::full_symint implementation by improving their error message, and returning a status type value.

Key Changes:

• Make tensor_methods::full and tensor_methods::full_symint return StatusOr<absl_nonnull XLATensorPtr>
• Improve error message on incompatible tensor shapes

Example:

torch.full((2, -2, 2), 1.5, device="xla")

Before:

Traceback (most recent call last):
  File "examples.py", line 5, in <module>
    torch.full((2, -2, 2), 1.5, device="xla")
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: Check failed: std::all_of(size.begin(), size.end(), [](int64_t dim) { return dim >= 0; }): Dimensions cannot be negative numbers (at torch_xla/csrc/tensor_methods.cpp:208)

Exception raised from operator& at torch_xla/csrc/runtime/tf_logging.cpp:26 (most recent call first):

After:

Traceback (most recent call last):
  File "example.py", line 5, in <module>
    torch.full((2, -2, 2), 1.5, device="xla")
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: full(): expected concrete sizes (i.e. non-symbolic) to be positive values, however found negative ones: [2, -2, 2]

Status Propagation Trace:
    From: CheckSizesArePositiveImpl at torch_xla/csrc/tensor_methods.cpp:427 (error: full(): expected concrete sizes (i.e. non-symbolic) to be positive values, however found negative ones: [2, -2, 2])
    From: full at torch_xla/csrc/tensor_methods.cpp:1818

Exception raised from MaybeThrow at torch_xla/csrc/status.cpp:121 (most recent call first):