#2064 function start_a_blank_case_note - Check if case note already open and open a new case note if needed

[MDR22]

Add functionality to start_a_blank_case_note to check if already on new or existing case note. If already on case note then it PF3s and then PF9s to open a blank case note. User had reported issues with scripts not correctly creating a case note when they were already in a case note.