Nuke: deep image exr loading

[jakubjezek001]

Is your feature request related to a problem? Please describe.
Deep image ex can occasionally be used in productions and we do not support loading them yet.

Describe the solution you'd like
enhancing actual LoadClip plugin
find some way how to identify exr in representation as deep images - OIIO can read metadata and flag it during publishing into version and save it into representation.data. So during loading this flag will tell the plugin to chose different Read node.
if deep image representation is identified then use DeepRead node.
rest is the same as normal Read node.

[cuID:OP-4468]

[jakubjezek001]

closing in favour of ynput/ayon-nuke#6