feat(calendar): add explained period feature and update translations

src/app/components/calendar-month/calendar-month.html

@@ -38,6 +38,7 @@
 								[class.end]="selectedDates.isEnd(day)"
 								[class.selected]="selectedDates.isSelected(day)"
 								[class.current]="dateKey === currentDate"
+								[class.explained-period]="isInExplainedPeriod(day)"
 								[class.context-only]="!isInHorizon(day)"
 								[class.eligible]="status?.kind === 'eligible'"
 								[class.ineligible]="status?.kind === 'ineligible'"