Task: Fix image upload / storage flow

[iolyd]

Task Description

We implemented the image upload flow in a rush and its current state is not really viable. Generated image variants do not really match UI uses and quickly lead to laggy behaviors when multiple images are loaded. Additionally, there is a poor relation between the schema structure and the variants selection. Variants information (name and storage url) should probably be stored in a single custom-typed json column rather than multiple loosely named columns.

List of actions

• [ ] Define image variants more rigorously
• [ ] Update db schema to json col(s) instead of urlSize and nameSize columns

[iolyd]

Implemented a more viable and future-proof approach through 73c0f762e006e3bbeb7f7c121a6c4c1252381e64