DEV-38840: cosmetic fix to the Pay Resident/Group floater in 2.0.

Previously the title for this floater was set to "" and a text string
was positioned over the title bar based upon whether you are paying a
resident or a group. This could mess up the position of the floater
"title" and was also truncating the "Pay Resident" title. Now, we use
setTitle() to actually set the floater title appropriately.