`app.modulesReady` should resolve when all modules are ready (not just dynamic imports)

[cmalven]

Currently, app.modulesReady is a promise that resolves when all dynamically imported modules are ready to work with. However, with some setups this could mean that while all dynamically imported modules are ready, initialModules might not be.

The ideally way to solve this would be to add promises even for initially imported modules, and have app.modulesReady resolve when all initially imported and dynamically imported modules are ready.

[cmalven]

Relevant code is around https://github.com/cmalven/modu/blob/main/index.js#L274