feat(aten): implement as_strided, resize_, _reshape_alias; refactor empty ops

[izzalDev]

Summary

This PR implements three previously stubbed ATen native operations for the OpenCL backend — as_strided, resize_, and _reshape_alias — and refactors the existing empty_memory_format and empty_strided implementations to delegate to the upstream at::detail allocation helpers, removing the bespoke make_opencl_tensor path.

Changes

• Add as_strided, resize_, and _reshape_alias to Minimal.cpp / Minimal.h, and register all three in TORCH_LIBRARY_IMPL.
• Refactor empty_memory_format to use at::detail::empty_generic and empty_strided to use at::detail::empty_strided_generic; remove the internal make_opencl_tensor helper.
• Remove the CPUFallback include from OpenCLMinimal.cpp; previously commented-out stub declarations in the header are replaced with real signatures.
• Tighten TORCH_CHECK messages across all ops (pin memory, non-strided layout, peer-to-peer copy).
• Reformat all touched files to the 80-column limit introduced in .clang-format.

Tests

• test_allocator.py: add zero-size allocation, multi-dtype, pin_memory error, and unsupported layout tests.
• test_minimal.py: add TestAsStrided, TestResize, and TestReshapeAlias test classes; extend TestCopyFrom with dtype mismatch, numel mismatch, and non-contiguous source cases.
• test_device.py: add lifecycle, is_in_bad_fork, and exchange_device binding tests.

Notes

• resize_ performs a memcpy-based reallocation when the new size exceeds the current storage; shrinking is metadata-only.
• Negative strides and negative storage offsets are explicitly rejected in as_strided; this is a current OpenCL backend limitation, not a general ATen constraint.
• The _copy_from peer-to-peer error message was reformatted to fit the 80-column limit; no functional change.

Checklist

• Code compiles cleanly against the target libtorch / OpenCL stack
• All existing tests pass
• New tests added for each new operation
• Formatted with clang-format (80-column limit)
• Docs / changelog updated (if applicable)