DIFF-01 [FEAT] Implement Diff functionality for 2 Graphs

[jahandaniyal]

Purpose

Implement basic Diff for Graphs functionality for comparing 2 graphs.

[Add more details later]

Acceptance Criteria

• [x] Implements graph intersection and graph difference
• [x] Pageview user-interface
• [x] Graphical User Interface (Cytoscape canvas to render graphs)
• [ ] PR documentation
  • [ ] Document API changes
  • [ ] Document UI changes (mainly GIFs and screenshots)
• [ ] User documentation
• [ ] API documentation in RAML
  • [ ] Add a screenshot of HTML docs generated from RAML here.
• [ ] Developer documentation in Wiki
• [ ] Python documentation in Code
• [ ] Write tests in Python