Quick Win Usability Improvements

[kmcginnes]

Once Graph Explorer is more reliable and performant, the next goal should be for usability.

These features are relatively straight forward to implement and don't require major changes.

• [Bug] Datetime property values are not shown in details view #122
• [Feature Request] Double click to expand only works if the node has <= 10 adjacent ones. Confusing UX #318
• [Feature Request] Node details are not selectable in search results #309
• [Feature Request] Clearing the canvas cannot be undone #310
• Show RDF language-specific values: rdfs:label, rdfs:comment, etc #124
• [Feature Request] Context menu when right clicking on a node can be improved to include more "one click" actions #322
• [Feature Request] Add a hover tooltip type box to nodes and edges #319
• [Feature Request] Add ID to the filter drop down for neighbor expansion #274
• [Feature request] Allow for default class where a rdf:Class does not exist. #61