This patch adds a module type parameter to
`ModuleLoaderBase::{CreateStaticImport,CreateDynamicImport},` and gets rid of a
bunch of hard-coded `JS::ModuleType::JavaScript.` However, the module type is
still hard-coded when we call `CreateDynamicImport` and `CreateStaticImport`.
Differential Revision: https://phabricator.services.mozilla.com/D218556