Implement longest common leading/trailing substring algorithms

[remes2000]

Description of new feature, or changes

Implement longest common leading/trailing substring algorithms

Checklist

• [x] Your branch is up-to-date with the base branch
• [x] You've included at least one test if this is a new feature
• [x] All tests are passing

Related Issues and Discussions

#8

People to notify

@manrajgrover @remes2000