Enable dtype memory

[StRigaud]

For now, only float type memory was possible in pyclesperanto.

The aim here is to make possible to create, push, and pull array of float, int32, int16 and int8 (and their unsigned equivalent).

• 'Create can now take a dType
• Push is now templated on numpy type
• Pull is now type specific: PullFloat, PullInt32, etc.

Possible Issue:

• ImageOperator python class to mimic Numpy API request import of the wrapper function _Pull instead of the pythonised pull which now manage type return. Not a bloquing issue but code quality could be improve if we could rely on the pythonised pull instead.
• Any uses of non-valide CLIc type, should be cast as float32. Tests are needed.

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How it look like for now :

import pyclesperanto as cle
import numpy as np

buffer_short = cle.create( (5,5), cle.int16)          # <-- create an empty buffer space of short type
buffer_int = cle.push( np,ones((5,5), dtype=np.int32) )    # <-- push an array of int type
arr_int = cle.pull(buffer_int)                        # <-- pull a buffer of int into an array of int