Group Tasks Shared Completion (#10515)

* WIP(groups): add shared completion prop
Also fix an issue where the Needs Approval toggle would not read/save 
correctly.

* fix(groups): save group options on task create
Also, correct count of assigned members when viewing user is among 
assignments

* fix(groups): display correct messages in two places

* fix(tasks): eliminate console error related to filtering
Also localize a group plans string

* WIP(groups): implement single completion for approval workflow

* WIP(groups): Add shared completion handling to no-approval-needed flow

* WIP(groups): cover approval flow case for all-assigned
Also save new field on initial task creation

* fix(tasks): use default sharedCompletion value when creating tasks

* WIP(tests): non-working draft test

* Added completed todo to group query

* WIP(group-tasks): fix bugs, add tests

* refactor(group-tasks): deleteMany op, add more tests

* refactor(group-tasks): move shared completion handling to lib

* WIP(group-tasks): broken refactor

* WIP(group-tasks): await all the things

* Turned complete master task to save

* WIP(group-tasks): show completed

* fix(filtering): don't try to filter if no list is passed

* refactor(group-tasks): load completed to-dos on demand, not at start

* fix(group-tasks): don't double up on repeat visits

* fix(group-tasks): include brief explanation in dropdown

* fix(group-tasks): improve wording some more

website/client/components/tasks/column.vue

@@ -362,7 +362,7 @@ export default {
           type: this.type,
           filterType: this.activeFilter.label,
         }) :
-        this.taskListOverride;
+        this.filterByCompleted(this.taskListOverride, this.activeFilter.label);
 
       let taggedList = this.filterByTagList(filteredTaskList, this.selectedTags);
       let searchedList = this.filterBySearchText(taggedList, this.searchText);
@@ -556,7 +556,11 @@ export default {
     activateFilter (type, filter = '') {
       // Needs a separate API call as this data may not reside in store
       if (type === 'todo' && filter === 'complete2') {
-        this.loadCompletedTodos();
+        if (this.group && this.group._id) {
+          this.$emit('loadGroupCompletedTodos');
+        } else {
+          this.loadCompletedTodos();
+        }
       }
 
       // the only time activateFilter is called with filter==='' is when the component is first created
@@ -594,6 +598,13 @@ export default {
         }
       });
     },
+    filterByCompleted (taskList, filter) {
+      if (!taskList) return [];
+      return taskList.filter(task => {
+        if (filter === 'complete2') return task.completed;
+        return !task.completed;
+      });
+    },
     filterByTagList (taskList, tagList = []) {
       let filteredTaskList = taskList;
       // filter requested tasks by tags