When adding customer contacts to the CC list of a case, allow searching by name, in addition to RHN id

Issue

• RFE Portal - Allow searching by First/Last name when CCing contacts in a ticket.
• When adding CC contacts to a ticket, customers can only search by RHN ID. In organizations with hundreds or thousands of contacts, this is impractical as often they don't know a user's RHN ID, but always know the user's name/last name.
• Customers would like the ability to search by name/last name, as well as RHN ID.