program: implemented decoder, added recreator encoder testing

added private decode function to the program model class to convert the
code of a program line into an rpn list and return a pointer to the list

added public line text function to the program model class taking a line
index argument that returns the recreated text for a program line by
using the decode function and the recreate function of the recreate
instance, which was also added to the program model class

added an instruction sub code access function to the program word class,
which is used by the decode function

in the tester class, the temporary check to report an error when
selecting an encoder test file with the recreate output option (-to) was
removed, and modified the run function to output the recreated program
output at the end if the recreate output option is selected by using the
new line text function of the program model class

added expected recreated output files for all three encoder tests (which
was recreated correctly); and updated test scripts and batch files to
run the encoder tests with recreation