Splitter enhancement: messaging lists

We should let splitter choose where to send responses depending on the situation, or desired channels.

Consider

• list of messaging IDs in splitter component configuration
• if list is empty, send to every registered messaging components

• change sendMessage method to accept list of messaging IDs to iterate over (passed from components) and send to the respective channels
• in this scenario, service components can have defined messaging IDs and request that splitter sends responses to the select few
• if passed list is empty, send to every registered messaging components

3. A combination of both to handle all cases with priorities in the following order:

• send to channels specified by messaging IDs passed to the sendMessage method in a list from service component
• if the passed messaging ID list is empty, use messaging IDs in splitter component configuration
• if the splitter component configuration messaging ID list is empty, send to all registered messaging components