Initial refactoring of widget code and infrastructure

- removed all sass files and "widget-styles" gulp task to now put widget table layout css inline in the HTML
- adding new "table.html" which is widget.html but with inline css and imports new "content.js"
- adding new "content.js" as a start to refactoring the core content code so it can accommodate custom layouts
- refactored "spreadsheet.js" to improve its flow and logic and create/initialize the content
- renaming "widget-scenarios" to "table-scenarios" and temporarily commenting out majority of tests