Fix warnings: DatabaseName' hides inherited member 'NuGetGallery.Operations.DatabaseTaskBase.DatabaseName' by removing the hiding members.
And refix build warnings about DatabaseName. Old fix was warning-fixing by build-breaking.
Merge pull request #1412 from NuGet/tilovell-FixDatabaseInheritedMemberWarnings

Fix warnings: DatabaseName' hides inherited member 'NuGetGallery.Operati...