Random Workout View Contrller Implementation

*UI Picker loads exercises from the exercise list
*Checks to make sure that exercise names are valid and not null before
loading them in the list
*Added UIPickerView method

TODO//Need to make sure that if the database is deleted, that the
exercise list also deletes itself so that the exercise list does not
contain previous exercises from the previous database

*Memory leak tested and no leaks were found with this commit.