Workspace version inheritance for monorepo packages

Packages without a version: field now inherit the workspace version automatically. This eliminates the need to keep 26 package.sgl files in sync with the workspace version.

- Changed package version default from "0.0.0" to #f - workspace-load-packages fills in workspace version for packages that don't declare their own - Removed version: from all 26 monorepo package.sgl files - Fixed test-package.sgl to use keyword syntax (was broken pre-existing)