add subroutine to delete arrays of tensors

[TomMelt]

This PR adds a subroutine (torch_tensor_array_delete) to delete arrays of tensors. This eliminate the need to manually loop over all elements of the array calling torch_tensor_delete, see e.g.,

FTorch/examples/4_MultiIO/multiionet_infer_fortran.f90

Lines 57 to 60 in 490272e

	call torch_tensor_delete(in_tensors(1))
	call torch_tensor_delete(in_tensors(2))
	call torch_tensor_delete(out_tensors(1))
	call torch_tensor_delete(out_tensors(2))

Which now becomes,

FTorch/examples/4_MultiIO/multiionet_infer_fortran.f90

Lines 57 to 58 in e24c380

	call torch_tensor_array_delete(in_tensors)
	call torch_tensor_array_delete(out_tensors)

• add torch_tensor_array_delete to delete arrays of tensors
• update tests
• update docs

[jatkinson1000]

@TomMelt First glance looks good.

However, we'll need any examples in the documentation and readme also updating if you can go through these as well please?

I also wonder if your original suggestion of having an interface to delete both an array or a single tensor is a better to simplify the subroutine options. However, I also see that the explicitness of two different routines is more 'Fortranic'.

[TomMelt]

@TomMelt First glance looks good.

However, we'll need any examples in the documentation and readme also updating if you can go through these as well please?

done

[jatkinson1000]

@TomMelt Thanks - I wonder if an addition to the API changes page to point out this new option might be useful, though not essential as the old function is preserved?

Also I added a comment above with an edit for your thoughts:

I also wonder if your original suggestion of having an interface to delete both an array or a single tensor is a better to simplify the subroutine options. However, I also see that the explicitness of two different routines is more 'Fortranic'.

[jwallwork23]

Nice. Neatens things up a bit.

[jatkinson1000]

A new thought on looking at some code today - perhaps we could have an interface torch_delete() that can take a model, tensor, or array of tensors and call the relevant deletion subroutine?