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/controllers/api-v3/user.js

@@ -304,11 +304,11 @@ api.deleteUser = {
 
     await Promise.all(groupLeavePromises);
 
-    await Tasks.Task.remove({
+    await Tasks.Task.deleteMany({
       userId: user._id,
     }).exec();
 
-    await user.remove();
+    await user.deleteOne();
 
     if (feedback) {
       sendTxn({ email: TECH_ASSISTANCE_EMAIL }, 'admin-feedback', [