Pull proxyWidget code out of SubgraphNode

This was needed from an organizational standpoint. For now, it requires
an ugly setTimeout to prevent proxyWidgets from being clobbered during
initialization, but this will be cleaned up later.

This also allows for the proxy widget code to have type checks ignored.
I fully intend to find a functional solution here, but this provides a
migration path where typechecking can be enabled for the rest of the PR
first

Also cleans up type checking on graph change in scripts/app.ts

src/extensions/core/index.ts

@@ -11,6 +11,7 @@ import './maskeditor'
 import './nodeTemplates'
 import './noteNode'
 import './previewAny'
+import './proxyWidget'
 import './rerouteNode'
 import './saveImageExtraOutput'
 import './saveMesh'