Removing node-sass and request package and adding sass instead

[lohitakshgupta]

Removing node-sass and request and adding sass package instead to resolve alert: https://github.com/microsoft/azure-devops-extension-sample/security/dependabot/38

Ran the following commands:
npm uninstall node-sass
npm install sass
npm audit fix (which removed request package from package-lock.json)

[dpaquette]

Need to review this more closely. I will do that first thing tomorrow morning. I'm not sure why node-sass is still in the package-lock.json