Literal string subscripts that include "/" now work

This fixes the problem documented at YottaDB/DBMS/YDBOcto#1034 (comment 1804235992)

Literal string subscripts that include "/" now work. The problem was that "/" characters in literal subscript strings were interfering with the "/" characters used as option separators in templates for different application subscript types (AIMTYPEs). The solution was to move the option selection prior to the substitution to create the trigger code from templates. A side effect of this change is that strings during substitution are marginally smaller.