Add compress script to apply gzip to assets not packed by webpack

[1000TurquoisePogs]

When v3 was made, the build script of the desktop changed from webpack to angular-cli.
As a result, our compression plugin is no longer used, and assets in the web folder do not get compressed.

Given that the command "gzip" is universally available on unix environments, I just created a node program that recursively goes through the web folder and runs "gzip" if a file is under a certain size limit and over a certain minimum size.
If the resulting gzip file isn't meaningfully smaller, it is removed. If it is small enough, the original file is removed.

The result is that this script can compress web folder contents without adding some npm library dependency.

To use this, it must be added to a build script.

Use as:

npm install
npm run build
npm run compress