vCardCollection: Expose the ::EDIT capability

It is implemented, but the collection didn't declare it.

This allows editing some vCard before sharing them to peers
using the built-in vCard sharing over SIP feature.

Change-Id: I49e41b3a7ad4965279c6bc57c380639179cd5489

src/fallbackpersoncollection.cpp

@@ -240,6 +240,7 @@ FlagPack<CollectionInterface::SupportedFeatures> FallbackPersonCollection::suppo
       CollectionInterface::SupportedFeatures::CLEAR      |
       CollectionInterface::SupportedFeatures::MANAGEABLE |
       CollectionInterface::SupportedFeatures::REMOVE     |
+      CollectionInterface::SupportedFeatures::EDIT       |
       CollectionInterface::SupportedFeatures::ADD        ;
 }