Enable grouping of same agents in the status overview from the Configuration UI

[mariusoe]

As a user, I want to be able to group agent entries (representing the same agent instance) in the "agent status overview" of the configuration UI, so that I quickly find the currently running agent and don't have to search through multiple entries which reference inactive instances.

---

Currently, each agent gets a unique ID which contains the process ID of the JVM process the agent is attached to. Due to this, as soon as an application is restarted, the agent overview of the configuration UI shows multiple entries (which refer to the "same" instance of an application) for the agent because of its unique ID. See the following screenshot.

Since the service name is unique most of the time, the UI should provide and option (e.g. using a checkbox) so that similar agent entries (equal attributes) can be grouped together in order to increase the readability of the whole view. When grouping is enabled, only the latest agent entry should be shown. It would also be helpful if the number of grouped agents is displayed - if there is more than one entry.

Example: