Refactor `ContactListAdapter` to be used for Introductions and Forum Sharing
This MR introduces an abstract BaseContactListAdapter
which provides
most of the adapter logic. The original ContactListAdapter
extends it to
show date and online status of the contacts.
The new ContactChooserAdapter
which is used for introductions extends
the ContactListAdapter
and adds logic for graying out contacts from
different identities than the currently used one.
A new ContactSelectorAdapter
extends the BaseContactListAdapter
and
allows to select multiple contacts. It offers a method to return a
collection of all selected ContactId
s.
Closes #292 (closed)