Add platform agnostic way to read environment variables

[markwolff]

Add a platform agnostic based way to read environment variables. We can add a single helper util here to ultimately read from process.env, global, window, etc.

On startup a pre-aggregated list of environment variables could be loaded into an environment holder, or the utility function could access an environment variable at runtime.

getEnvironmentVariable(name: EnvironmentVariable): string

_Originally posted by @obecny in #1153 (comment)

[obecny]

@markwolff are you already working on that, or it's available to grab ?

[markwolff]

I haven't started on it yet. You can grab it