Adding resizable images

[notanengineercom]

#10181
I worked this weekend and added the ability of resizing images. They are being declared in the config.json (disabled by default). I also changed a bit of the sharp image function, with better image compression and added an optional deletion of the original image.

[kirrg001]

@allouis As you took over #10181, could you please reply to this PR? Thanks 👍

[allouis]

hey @notanengineercom Thanks for your contribution ☺️ As was mentioned in #10181 we need something a little more flexible and preferably without adding extra deps! I'm going to close this as we already have something put together which satisfies this. Thanks again 👻

[notanengineercom]

@allouis yes sure, no problem. I just recommend you considering imagemin, because sharp (even though it's the fastest) makes image files bigger in size when you upload an optimized pictures (so when you scale down the image it's often bigger than the original).