UX - UI improvements

[bstabler]

• Parse JSON settings files and create controls (button, drop downs, etc.) for content since these are difficult for the user to edit. All input CSV files are expected to be edited in Excel.
• Remove non-essential stuff
• Later, allow user to edit and run multi-run configuration and scenario viewer

[bstabler]

also, do #160, update the tutorial as a result of these changes #159, and run the single run reporting script as part of a run.

[bstabler]

also investigating why the GUI has some relatively long delays #99

[bstabler]

This is a more specific list of improvements that we're making. This list supersedes the items above.

• Remove “VisionEval” from the title
• Remove rhandsontable usage since it appears to be really slow
• Replace model and run parameters with DT tables
• Pre-preprocess run parameters json file to ensure one item per key. Basically get all items, check if length > 1, and if so, concatenate into comma separated list. Post-process when writing back out to json after editing the table.
• Rename model specification to Inputs.
• Move input tables to DT rendering
• Remove data store and model spec from Model Specifications tab
• Remove data store and model store from outputs tab
• On outputs tab, add Run button for export_output_to_csv.R and create DT table of results
• Commit to GH add_scenarios branch
• Update test system for VEGUI if needed
• Update documentation and tutorial