Release v4.121.0

Changed

• Generated Common concept, type and enum files now use short type names with using directives instead of global::-qualified names. The usings sit inside the file-scoped namespace and are rooted with global::, so code you add in Customizations/ cannot change what a generated name refers to; names that cannot be proven safe stay qualified. Existing generated applications see a one-time text change in these files on their next regeneration; other generated files follow in later releases. (part of #424)
• The rendered scaffold's .editorconfig places using directives inside the namespace for generated code. (part of #424)
• Do not declare your own types inside generated namespaces; see https://github.com/Cratis/Stage/blob/main/Documentation/guides/customize-rendered-application.md. (part of #424)