show only bean name proposals on qualifier annotations when type matches

[martinlippert]

At the moment, the content-assist for the qualifier annotation shows up bean names and existing qualifier values, independent of the exact definition of the injection point. We could trim down the list of proposals by listing only those bean names that match the type of the injection point.

As another step we could also reduce the list of existing qualifier values to those that where used on bean definitions that match the given type of the injection point.