Infinispan module attribute needs to support multiple values

The cache-container and remote-cache-container resources in the Infinispan subsystem have a module attribute that is used to dynamically load externalizers used to configure marshalling for capabilities associated with these resources.

Additionally, this attribute is also used to load Infinispan modules (e.g query, multimap, hibernate, etc.).

Several users have had issues with configuring the marshalling of a custom cache because the module to which their cache container is associated does not know about their module. Users wanting to a specific Infinispan module has a similar issue.

Currently, the only way to load marshalling configuration from multiple modules is through the use of module dependencies (using services="import"). This causes lots of unnatural service dependencies, which complicates the ability to build fine grained galleon layers.

In order to support the use of multiple modules for a given cache-container, and also to support marshalling for multiple modules, we need to allow these resources to be associated with a list of modules, instead of a single module.

Thus, the "module" will need to be replaced by "modules", where the former becomes an alias for the latter, with some translation logic to convert multiple values to a single value.