instructor can download student list with separated first name and last name
simplify split name method and move it into stringHelper class
fix typo
1. fix typo
2. add test for split name method
fix typo and add case for empty string full name
1. correct the wrong "splited" word
2. improve the header comment
1. extract removeExtraSpace into a new method
2. separate above method from splitName method
3.add test for removeExtraSpace method and modify the test for splitName method
Merge branch 'master' into 74016362
[Fixes #74016362] instructor can download student list with separated first name and last name