Add option to skip image resizing and rely on resizing done externally

[stefanistrate]

Hi Dan,

In my case (for Wildlife Insights), I want to resize images before calling process_image(). Would you like to support this use case in the main repo through a new parameter?

Ștefan

[agentmorris]

Looks non-controversial, and if we can support Wildlife Insights without forking little bits of inference code, that's a win/win. I confirmed the following in testing:

• This change has no impact by default
• If I hard-code skip_image_resize to "True" and supply random images, most images fail (this is WAI)
• If I hard-code skip_image_resize to "True" and supply images already resized to 1280, I get the same results as I do with skip_image_resize==False
• If I hard-code skip_image_resize to "True" and supply images already resized to some other size that's still a stride boundary, things mostly don't fail, but I get slightly different results (still reasonable, but different)

I believe that's all WAI, merging.