App/Backend - Previous images in form submitting

[alexzhang1618]

Describe the feature to implement.

• When we create a form with image submits (think AddJob, user profiles, driver registration) and there are previously existing images associated with it (this happens when updating a job/user profile), we make a dispatch to ImageUploadContext to SET_IMAGES with the previous image IDs.
• We want to automatically populate the form with the previous image IDs and submit them when we submit the form to the backend.
  • If possible, we should try to save the images in the backend without deleting the old images that should be kept (this might include editing some of the backend image saving functionality)