Support for implementation-defined translation overrides

Sometimes it will be necessary for administrators to define overrides for translations in the various frontend applications. The proposed syntax for this is to extend configuration schemas to support translations overrides like this:

{
  "@openmrs/esm-login-app": {
    "Logo": "pih.png",
    "Translation overrides": {
      "en": {
        "family": "Family"
      },
      "es": {
        "family": "Familia",
        "username": "Tu email"
      }
    }
  }
}