Node Focus View Visualization

[zwelz3]

Viewing the LPG graph for a specific node (or node type e.g. rdf:Class) can be informative as part of:

• Ontology visualization
• RDF to LPG transformation
• etc.

This representation, of a node, its outgoing connections to other nodes, and its internal data representation (as data properties), will be referred to as Focus Mode since it allows users to focus on a specific node of interest.

This ticket will be split into two parts:

1. develop the initial focus mode visualization
2. expand existing tools (e.g. FileManager) to support to support graph instances and ontology files

Blocked by #91

[zwelz3]

During internal review, we have decided to forgo a focus view in favor of improving the GraphExplorer capabilities. The goal is for the GraphExplorer widget to support selecting individual nodes, which will mimic the concept behind the focus view, but also allow for additional exploration.

See #98