Move hard coded widgets to external asset file

[royfalk]

The asset file controls.json now holds the various widgets drawn in the base computer.

Notes:

• This is a work in progress and will require additional PRs/commits to migrate everything.
• This is a breaking change so if there's an upcoming release, it's probably not for it.
• There's a matching PR in asset production with the controls.json file.

Code Changes:

• [No] Have the PR Validation Tests been run? See https://github.com/vegastrike/Vega-Strike-Engine-Source/wiki/Pull-Request-Validation. This is an isolated PR. I've focused on changes to the base computer. I've taken screen shots of all screens and compared them to the changed version. I've also tested the various screens to make sure nothing broke.

Issues:

• None identified

[stephengtuggy]

Looks good to me!