Reimplement adding comics to a reading list

[mcpierce]

Since the reading list interface has been re-factored, the means for adding comics to a reading list need to be redone.

Preconditions:

1. The user selects one or more comics.
2. A new menu item is added to each reading list's context menu labeled "Add Selected Comics"

User Story:

1. The user right clicks on one of the reading lists.
2. The user selects the "Add Selected Comics" menu item.
3. A confirmation dialog is shown.

Postconditions:

1. If the user selects No:
   • No changes are made.
   • The selections remain selected.
   • No reading list entries are created.
2. If the user selects Yes:
   • The selections are cleared.
   • The selected comics are added to the specified reading list.