Various results table improvements

[michaelnchin]

Issue #, if available: N/A

Description of changes:

• Disabled line wrapping for result rows
• Reverted font of results to type monospace and size 12px
• Fixed a bug where results table would display ambiguous Loading... message for empty results sets
• Fixed a JupyterLab-specific bug where the results table would render with a much greater width than the actual page size

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