FEATURE: Add picture attachments to posts

[JoelWiebe]

Feature

Overview
Add ability to upload and view images in all posts

Details
Migrate image storage from deprecated Firebase implementation to MongoDB and add the ability to attach an image to each post

Tasks

• Implement MongoDB database implementation for image storage
• Test implementation using the existing background image for canvases feature
• Add button to each post in edit view to upload an image
• Add a button to each post in the edit view to delete the image (include a confirmation dialogue)
• Perform angular compression of the image and store in MongoDB
• Display image at a default max height and max width in the view post modal
• Display an icon on the post card on the canvas, bucket view, workspace, etc. if the post contains an image