Implement drag-and-drop for image uploads

[latin-panda]

Description

Currently, Web Forms only supports manual file selection via the file explorer. We need to implement drag-and-drop functionality to improve the user experience for file, image, and video uploads.

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Checklist

• Does it need UI/UX design?
  • Yes. Describe the UI/UX requirements or attach a Figma link in the "Design" section.
  • No
• Does it need API design?
  • Yes. Specify the endpoints, methods, or data structures needed.
  • No
• Does it need design around state flow?
  • Yes. Outline the state flow requirements.
  • No
• Does it need a test plan?
  • Yes. Add the test plan as a comment in this task or attach the document.
  • No

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User Stories

• As a [user type],
  I want [functionality],
  so that [benefit].

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Design

The image upload will follow the drag and drop design for video upload.

The Edit coordinates dialog - upload file, will follow the design for file upload

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Dependencies

• File upload question type #370

[latin-panda]

Edit coordinates dialog - needs design
Upload image question type - needs design
Upload file question type - it has design

[garethbowen]

@latin-panda I've assigned this to myself because I was working on drag and drop for upload files as part #370 . I think the upload image and video is very similar so I'm tempted to do that at the same time so I can get the right level of abstraction.

However the edit coordinates dialog feels very different to me, and is waiting on design. How would you feel about splitting that one out?

[latin-panda]

@garethbowen Yes, it's okay to split it. If I recall correctly, @alyblenkin wanted to use the same drag and drop design as in the file upload question type.

[garethbowen]

Split out coordinates to: #739