Fix development environment related proxy bugs

[otahontas]

Description

Fixing bug with development proxys and docker. Also setting backend as requirement for frontend in readme.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Changes Made

• Change proxy settings from package.json to proxy-module. Proxy is by default "localhost:5430", unless set to different with env variable.
• In development docker-compose, change backend proxy to be default container name for backend. Also add frontend container to same docker network with backend.
• When files were in folder called development, docker-compose added all launched containers to project called "development" by default. This created nameclashes, but moving files to project root leads project to be called "metadata-submitter-frontend"
• Update readme according to these fixes.

Testing

• Tests do not apply

Mentions

Open for other solutions as well