Murali-group/PathLinker-Cytoscape: Add cyREST API Functionality

Major update to PathLinker which includes new cyREST API functions, code refactors, and bug fixes.

PathLinker app version: 1.3 -> 1.4 PathLinker API version: 1.0 (new!!!)

Feature:

• Now Compatible with Cytoscape 3.6 (Not backward compatible with Cytoscape 3.5).
• Restrict k and edge penalty text field to only allow integer and double numerical inputs from user.
• Implement two REST API function "run", one for selected network and one takes user input network SUID.
• Include Jupyter Notebook examples on using the automation features

Development:

• Refactor runKSP, create subgraph/view processes into task classes, now better align with OSGi design.
• Refactor validation and error handling codes for reducing duplicated codes.
• Reorder the packages for organization purposes.
• Update pom.xml file to include new features and be compatible with Cytoscape 3.6

Bug fix:

• Fix the issue where submit button enables when there aren't any inputs in the source/target fields.
• Remove unneeded error messages "source/target empty". fix the issue where more than one space between nodes in source/target text field results in adding additional node with empty name.
• Fix the issue where the network combo box is not updated correctly with selected item after creating a new network