Rewrote Promise.then() with async/await

src/app/app.component.ts

src/app/components/app-setup/app-setup.component.ts

...p/components/calculator-list/calculator-list.component.ts

...ents/dialog-load-session/dialog-load-session.component.ts

src/app/components/fixedvar-results/results.component.ts

...app/components/generic-calculator/calculator.component.ts

src/app/services/app-setup.service.ts

src/app/services/formulaire.service.ts

src/app/services/internationalisation.service.ts