Update NPM dependencies (resolve npm audit warnings, update angular)

• Fix npm audit vulnerability warnings
• Update Angular to 7.2.7 & Angular CLI to 7.3.2 (using ng update @angular/core ...) #1 (closed)
• Update other dependencies if possible
• Apply Angular diff version https://github.com/cexbrayat/angular-cli-diff/compare/7.0.4...7.3.2