Add image sizes support for image choice field

[omarkasem]

• Add image sizes support for image choice field like it does in gutenberg options
• It's important also for Gravityedit so we can pass the image size to the .js file so we can maintain the same size for gravityview and graviyedit related to https://github.com/GravityKit/GravityEdit/issues/265

[rafaehlers]

@omarkasem Just to clarify, now we need to implement support for Image Choices styles and sizes on GravityView's block, right?

[rafaehlers]

[omarkasem]

@omarkasem Just to clarify, now we need to implement support for Image Choices styles and sizes on GravityView's block, right?

Yes, So we would have the same look like Gravity forms because right now we just have a fixed size