Environment field not following fabric.mod.json v1 spec

[Prospector]

The spec for v1 here says that environment can be an array of strings, however the parser doesn't allow this.

Seems to be a bit of an oversight, and the API is not set up to handle it this way, as it only returns a string.

Related issue: https://github.com/TerraformersMC/ModMenu/issues/361

This is kinda needed for mods that are single-sided but can be installed on either environment.

[sfPlayer1]

It is not really expressing this, but whether the mod gets loaded or not. The c<->s network dependence is to be expressed differently soon.