Add gzip compression in nginx configuration to reduce file size

[yodeyer]

Description

The purpose is to reduce the loading time by reducing the amount of data transferred.

With a simulated 100 mbps internet connection :

• before :
  
• after :
  

gzip_static reduces the CPU used by nginx, by avoiding to gzip files for each request.

Motivation and Context

It reduces loading time by more than 1.5 second (and even more on a slow internet connection).

How Has This Been Tested?

I compared network tab in Chrome Developer Tools with and without gzip.

Checklist

My PR contains...

• No code changes (src/ is unmodified: changes to documentation, CI, metadata, etc.)
• Dependency changes (any modification to dependencies in package.json)
• Bug fixes (non-breaking change which fixes an issue)
• Improvements (misc. changes to existing features)
• Features (non-breaking change which adds functionality)

My changes...

• are breaking changes to a public API (config options, System API, major UI change, etc).
• are breaking changes to a private API (Redux, component props, utility functions, etc.).
• are breaking changes to a developer API (npm script behavior changes, new dev system dependencies, etc).
• are not breaking changes.

Documentation

• My changes do not require a change to the project documentation.
• My changes require a change to the project documentation.
• If yes to above: I have updated the documentation accordingly.

Automated tests

• My changes can not or do not need to be tested.
• My changes can and should be tested by unit and/or integration tests.
• If yes to above: I have added tests to cover my changes.
• If yes to above: I have taken care to cover edge cases in my tests.
• All new and existing tests passed.

[shockey]

please build

[shockey]

thanks @yodeyer!