Fix Gremlin visualizations failing to render with UUID type IDs

[michaelnchin]

Issue #, if available: N/A

Description of changes:

• Fixed an issue where the graph widget would fail to render for Gremlin query results containing vertex or edge IDs values of UUID type, due to a JSON serialization error.
• Catch exceptions from gremlin_network and Force widget generation separately, to make visualization debugging easier.
• Related question on StackOverflow: https://stackoverflow.com/questions/75986863/aws-jupyter-notebook-dont-show-graph-tab-after-changed-gremlin-settings

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.