Display the state of the async semantic analysis on document summary tab

Make the LocalEntityService provide a method to query the state of any analysis ongoing on the current document. The states should be transients (at the service level, protected for concurrent calls, without any call to a persistent store.

Add an a4j:poll to automatically refresh the state of the linked entities when a analysis is under way.

If no analysis is underway, display a button to manually ask for a new analysis.