Update to remove npm audit vulnerabilities

[mechaffin]

Type of change?

• [ ] Bug fix
• [ ] New feature
• [x] Enhancement
• [ ] Breaking change (breaks backward compatibility)

Description, Context, Motivation

1. Update package versions of react-scripts and react-svg.
2. Converted to use of simplified scripts since newer version of react-scripts supports SCSS out of the box.
   • Remove unneeded dependencies
   • Update all CSS file references to SCSS
3. Updated version of node-sass to remove deprecation warning when server starts.
4. Removed unused packages.
5. Upgraded most packages to latest versions. In a few cases, like rxjs and redux-observable, they were upgraded to the latest compatible version which did not require significant refactoring of our code.

Checklist:

• [x] All tests passed
• [x] The code follows the code style and conventions of this project
• [ ] The change requires a change to the documentation
• [ ] I have updated the documentation accordingly

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