Fix header to the top of the table in Progress page

Author: Hrvoje Vucic

client/components/repository/Workflow/Overview/index.vue

@@ -3,8 +3,9 @@
     @click:row="selectActivity($event.id)"
     :headers="headers"
     :items="items"
+    height="100%"
     item-class="class"
-    disable-pagination hide-default-footer
+    disable-pagination hide-default-footer fixed-header
     class="overview primary lighten-5">
     <template #item.name="item">
       <overview-name v-bind="item" />