Half matrix and components

[yhmtsai]

This PR adds the matrix and components (like arrary/device_matrix_data) with half precision support

Also, to avoid touch the files, which are not related to this PR, I add several type list with half additionally.
For example, RealValueTypes -> RealValueTypesWithHalf and next_precision -> next_precision_with_half
(We will add bfloat16 in the future, so maybe do not use Half)

for the friend and corresponding function

friend class <prev<value_type>> // class previous precision can access this
function(class <next<value_type>>) // it can access the class with next precision because it is class with previous precision of class with next precision.

If we only use next in friend and function

friend class <next<next<value_type>>>
function(class <next<value_type>>)

Moreover, the second one does not work when we fallback the next_precision_with_half to next_precision by disabling half because next<next<value_type>> is value_type without half now. However, the first one always work.

TODO:

• merge Half base type #1706
• add as_device_type to sycl for gko::half <-> sycl::half move to Sycl device_type mapping #1710
• ensure we do not call 16-bit fake atomic