remove (most) submodules

[sdumetz]

See this script

Effort ongoing here

Squashing (or not) the commits from the submodules into the same folder is easy enough. Removing dead code might be more work intensive.

[sdumetz]

Identified a bunch of unused files with this knip config:

"knip": {
        "entry": [
            "source/client/ui/explorer/MainView.ts",
            "source/client/ui/story/MainView.ts",
            "source/client/ui/launcher/MainView.ts",
            "source/client/ui/mini/MainView.ts"
        ],
        "project": ["source/client/**/*.ts", "libs/**/*.ts"],
        "paths":{
            "client/*": [ "./source/client/*" ],
            "@ff/core/*": [ "./libs/ff-core/source/*" ],
            "@ff/graph/*": [ "./libs/ff-graph/source/*" ],
            "@ff/browser/*": [ "./libs/ff-browser/source/*" ],
            "@ff/ui/*": [ "./libs/ff-ui/source/*" ],
            "@ff/react/*": [ "./libs/ff-react/source/*" ],
            "@ff/three/*": [ "./libs/ff-three/source/*" ],
            "@ff/scene/*": [ "./libs/ff-scene/source/*" ]
        }
    }

[sdumetz]

See https://github.com/Smithsonian/dpo-voyager/pull/284