FROS-Use Supabase Storage

[multimokia]

Feature Description

Replace the avatar_url or image_url fields for users/servers with references to supabase storage

Use Case

Currently, we rely on using urls to external sources for profile pictures/server images, however this isn't great as the resource is not guaranteed to load, likewise it also means we have no real means of handling users uploading their own images/attachments for messages

Prerequisites

• This requires a change to our tables to accomodate for the linkage to buckets
• This also requires a setup for our buckets for all features (message attachments/servers/avatars)

Any additional remarks:

Summary of additional changes