fix(storage-resize-images): maintain aspect ratio of resized images

[gregives]

The extension documentation says

This extension keeps the aspect ratio of uploaded images constant and shrinks the image until the resized image’s dimensions are at or under your specified max width and height.

However, it doesn't currently do that: this pull request fixes it.

Fixes #2106

[cabljac]

Thanks for your contribution, and your patience in getting this fixed! I will put out a new release with the fix soon.

[ralphferguson]

@cabljac & @gregives — do you think that this value could be configurable? I have essentially no experience with coding solutions for plugins like this (and the associated input field), but I'd be happy to look into it with some guidance, as I believe this would be a useful parameter to configure. What do you both think?

[gregives]

Hi @ralphferguson, this option is actually configurable already, it is called "Sharp constructor options for resizing images" and it will override these default options

[ralphferguson]

Fantastic! Thanks, @gregives!