Switch to EncodedCommand to help coder.com

[TylerLeonhardt]

PR Summary

An alternative to fixing #1772. This will base64 encode the command that we want to run and use PowerShell's -EncodedCommand to make sure the command runs properly.

Unfortunately, -EncodedCommand assumes Unicode... in Node, we have utf16le. I want to test this on all platforms before this goes in.

Test checklist:

• Window
• macOS
• Linux
• Coder.com

PR Checklist

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Please mark anything not applicable to this PR NA.

• PR has a meaningful title
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  • If the PR is work in progress, please add the prefix WIP: to the beginning of the title and remove the prefix when the PR is ready

[TylerLeonhardt]

Removed WIP!

[rkeithhill]

LGTM but did you intend to update package-lock.json with this PR (or did it sneak in)? It's not obvious to mean when we should be checking in the lock file.

[TylerLeonhardt]

I saw that it was updated and said, "eh, I'll leave it in".

I think we should maybe make sure it's never in a PR and rely on something like:
https://greenkeeper.io

To be the only one to update it. (it does, I checked)