Updates to Equation Sandbox Widget

Full list of issues here:
https://clu.cdl.ucf.edu/materia/equation-sandbox/issues
- [ ] Send scores back to RealizeIt
- [ ] Graph assessment
- [ ] Add graphing
- [ ] Convert from iframe to Guest widget
- [ ] Add sliders to variable inputs
- [ ] UI/UX upgrades to current version
- [ ] Include google fonts
