[eas-cli]: warn user on missing primary locale

[luke-h1]

Why

This PR warns the user if an app's metadata they're attempting to update/add is missing the primary locale (and/or if they have another non-primary locale in their config). Providing a non-primary locale while you are missing primary locale can cause some confusion as it will show up blank in the ASC's dashboard

How

Log a warning to let the user know they might want to fill out the primary locale and/or change the app's primary language

How did you build this feature or fix this bug and why?

1. Before creating apple tasks, we get the locale config.getLocales() and check whether the user has provided an empty object for their primary locale and whether they are using any non-primary locales i.e.

// store.config.json 

en-gb: {}
en-us: { title: "cool app", description: "cool stuff" }

Test Plan

Unit tests - not sure if there is a more automated / interactive way of building the CLI and testing a version so I just went with unit tests for the time being! happy to add more test coverage if there's a better way though

[luke-h1]

/changelog-entry chore warn user on missing primary locale