Make jump labels compatible with i18n/translation

mixins/jumpLabel.js

@@ -0,0 +1,12 @@
+export default {
+  methods: {
+    getJumpLabel(seconds) {
+      const val = Number(seconds)
+      if (isNaN(val)) return ''
+      const useMinutes = val >= 120 // keep 60s as seconds
+      const key = useMinutes ? 'UnitMinutesShort' : 'UnitSecondsShort'
+      const unitValue = useMinutes ? val / 60 : val
+      return this.$getString(key, [this.$formatNumber(unitValue)])
+    }
+  }
+}