Add CONV_TRANSPOSE_2D for Metal

[iliailmer]

This PR adds Metal-based implementation of CONV_TRANSPOSE_2D operation (#14909)

TODO:

• Tests

[ggerganov]

Add the necessary requirements for the input tensors here:

llama.cpp/ggml/src/ggml-metal/ggml-metal-device.m

Lines 649 to 651 in a190a9d

	case GGML_OP_CONV_TRANSPOSE_1D:
	case GGML_OP_CONV_TRANSPOSE_2D:
	return true;

For example, the implementation assumes that src0 and src1 are contiguous.

[iliailmer]

Added the checks for type, and is_contiguous checks as well.

[ggerganov]

I wonder if it would be more efficient to have KH x KW threads in each threadgroup, instead of just 1.

Would you like to try that in this PR or in a follow-up PR?

[iliailmer]

yeah, let me try it out in this one. i should be able to do it by the end of the week or so