Re-examine if a consumer module should load bundles from unnamed module

Resource bundles are typically private to the application (i.e. consumer, caller of ResourceBundle.getBundle).

Two scenarios of typical deployments:
1. resource bundles are in the same JAR as in the consumer
2. resource bundles and consumer are two separate JARs

It is not unreasonable to expect that the consumer migrating to a named module can easily migrate the bundles together:
1. consumer and bundles are in one single named module
2. consumer and bundles must be migrated to named modules at the same time

It's unlikely that existing consumer downloads the resource bundles from a 3rd party JAR file that the consumer has no control about.

This issue is to re-examine if a consumer in named module should simply find resource bundles from named modules only via service providers and the local resource bundles in the consumer module.

For other cases, including consumer is unnamed module and fallback cases to the legacy classpath resource bundle loading, it will only find resource bundles from unnamed modules and not from named modules.