Add free-form crop

[ajlende]

#21024 introduced cropping with fixed aspect ratios. Sometimes, however, it would be nice to crop the image without being restricted by the available aspect ratios like in the original prototype.

Tasks

• Add ability to free-form crop images from within the editor canvas (do we need to introduce a library for this?)
• Improve visibility of cropping presets, so that after entering cropping mode, a user can quickly toggle between presets (or drag the free-form crop) without having to open a dropdown menu
• Ensure that any added cropping tools can easily be added elsewhere, e.g. within a DataViews-powered Media Library as in: Phase 3: Collaboration > Media Library #55238

[mrfoxtalbot]

Thank you for reporting this @ajlende. I believe this is being discussed in #38990

I think we can close this issue in favor of the other one as it has a much lengthier discussion.

[ajlende]

#38990 refers to the aspect-ratio CSS property that doesn't make edits to the image.

This issue refers to the actual image editor adding a drag crop interaction in conjunction to the zoom crop that exists.

[andrewserong]

I know this is an old issue, but it'd be good to revive as there's still a need for good freeform cropping tools in the block editor. Another thing to look at is the visibility of the cropping presets. Currently, once you enter cropping mode, you need to know that this item in the toolbar allows you to select from cropping presets. I observed a user who was unable to find this dropdown after activating the cropping mode, so I'm wondering if while looking at free-form cropping, if we can also look at the visibility of the controls to select from presets. This is the dropdown I mean:

I've updated the issue description to reflect this note.