add new omit_first_ticklabels and omit_last_ticklabels property to axes

We would like to make use of an omit_first_ticklabels and 'omit_last_ticklabels' property on the axes. The property should allow to hide the first X or last X ticklabels, which would otherwise appear. This can be used to create cleaner and more refined print charts in scenarios, where the last or first label is not desirable or to close to the outer border of the chart to look visually appealing.

The same effect could be achieved with the new labelalias property by replacing the last or first label with an empty string, but the proposed method would be more intuitive and would also work well for automated data-updates, which might influence the range.

The new properties should take integers as input.

Commencez par localiser la manière dont les propriétés des axes et les libellés des graduations sont définis et rendus ; l’issue ne mentionne aucun fichier ni test. Ajoutez des propriétés entières permettant d’omettre les premiers ou les derniers libellés des graduations X, assurez-vous qu’ils restent corrects lorsque des mises à jour automatisées des données modifient la plage, et vérifiez que les libellés demandés sont masqués dans les graphiques obtenus.