Refactor some of thie chips code

VisibleRecipientChip and InvisibleRecipientChip had a lot of the same
code, so I moved it all into a delegate class. This resulted in a
bunch of "RecipientChip" classes, so I moved them all into their own
sub-package.

Change-Id: I01dfc931e006270dd37721c73e7bc3c0e7b67515