Replace deprecated dataArray with toUnsafeView

[asnt]

Following the hint.

[asnt]

Tests fail with Nim 1.0.x.

[mratsim]

The issue can probably be solved by:

• importing std/typetraits in tensor/initialization.nim
• exporting std/typetraits in tensor/algorithms.nim
• using mixin DistinctBase in toUnsafeView

https://github.com/mratsim/Arraymancer/runs/4669608372?check_suite_focus=true#step:23:390

This looks like another instance of the generic sandwich nim-lang/Nim#11225

[asnt]

@mratsim Thank you. I tried the suggestion without luck.
Does distinctBase exist in nim 1.0.x?:

# test.nim
import std/typetraits
echo type(distinctBase)

# Not OK.
$ choosenim 1.0.10
$ nim c -r test.nim
[...]
/home/u/Arraymancer/test.nim(2, 11) Error: undeclared identifier: 'distinctBase'
# OK.
$ choosenim 1.2.16
$ nim c -r test.nim
[...]
None

[Clonkk]

@mratsim I believe this PR can be closed after :

• Stop using deprecated dataArray #570
• Remove deprecated dataArray #569

were merged

[Vindaar]

Closing as unnecessary as mentioned by Clonkk. Thanks @asnt though and sorry for not getting it merged!