Factorized search for the longest variating param

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

...mponents/pab-profile-chart/pab-profile-chart.component.ts

...e-results-selector/variable-results-selector.component.ts

src/app/formulaire/definition/form-compute-pab.ts

src/app/results/var-results.ts

src/app/util.ts