Upgrade to mongoose 7 (#14971)

* remove some unused dependencies

* update mongoose version

* make common tests pass

* Make unit tests pass

* make api v3 integration tests pass

* fix lint issues

* fix issue with package-lock

* fix(lint): we don't need no .js

* fix(lint): update to latest config-habitrpg

* chore(npm): update package locks

* fix(test): replace deprecated fn

* chore(package): update eslint-habitrpg again

* fix(lint): server linting

* fix(lint): client linting

* fix(client): correct mangled common imports

* chore(npm): update package-locks

* fix(lint): punctuation, module

---------

Co-authored-by: SabreCat <sabrecat@gmail.com>
Co-authored-by: SabreCat <sabe@habitica.com>

website/server/models/challenge.js

@@ -119,7 +119,7 @@ schema.methods.addToUser = async function addChallengeToUser (user) {
     { $push: { challenges: this._id } },
   ).exec();
 
-  return !!result.nModified;
+  return !!result.modifiedCount;
 };
 
 // Returns true if user can view the challenge
@@ -339,7 +339,7 @@ schema.methods.unlinkTasks = async function challengeUnlinkTasks (user, keep, sa
       removeFromArray(user.tasksOrder[`${task.type}s`], task._id);
     }
 
-    return task.remove();
+    return task.deleteOne();
   });
   user.markModified('tasksOrder');
   taskPromises.push(this.save());
@@ -361,7 +361,7 @@ schema.methods.closeChal = async function closeChal (broken = {}) {
   const brokenReason = broken.broken;
 
   // Delete the challenge
-  await this.model('Challenge').remove({ _id: challenge._id }).exec();
+  await this.model('Challenge').deleteOne({ _id: challenge._id }).exec();
 
   // Refund the leader if the challenge is deleted (no winner chosen)
   if (brokenReason === 'CHALLENGE_DELETED') {
@@ -403,19 +403,21 @@ schema.methods.closeChal = async function closeChal (broken = {}) {
       ]);
     }
     if (savedWinner.preferences.pushNotifications.wonChallenge !== false) {
-      sendPushNotification(savedWinner,
+      sendPushNotification(
+        savedWinner,
         {
           title: challenge.name,
           message: shared.i18n.t('wonChallenge', savedWinner.preferences.language),
           identifier: 'wonChallenge',
-        });
+        },
+      );
     }
   }
 
   // Run some operations in the background without blocking the thread
   const backgroundTasks = [
     // And it's tasks
-    Tasks.Task.remove({ 'challenge.id': challenge._id, userId: { $exists: false } }).exec(),
+    Tasks.Task.deleteMany({ 'challenge.id': challenge._id, userId: { $exists: false } }).exec(),
     // Set the challenge tag to non-challenge status
     // and remove the challenge from the user's challenges
     User.updateMany({