Add casting of numpy, meta, raw, images

[DanicaSTFC]

The casting of int8, int16, int32 etc for numpy, meta and raw files to 16uint needs to be added (similarly to TIFF and NEXUS). This is because the core code only reads data in uint8 and uint16 bits. the parameter defining this is "vol_bit_depth". See

iDVC/src/idvc/io.py

Line 1013 in 230973e

def save_tiff_stack_as_raw(filenames: list, output_fname: str, progress_callback, start_progress, end_progress) ->None :

for the casting of TIFF images.

See #387 for more details on this topic.

In #387 I was only able to add one warning. The load methods in io.py such as

iDVC/src/idvc/io.py

Line 253 in d49b738

def loadMetaImage(**kwargs):

need to be revisited.