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

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

test/helpers/api-unit.helper.js

@@ -11,9 +11,9 @@ import * as Tasks from '../../website/server/models/task';
 
 export { translationCheck } from './translate';
 
-afterEach(done => {
+afterEach(() => {
   sandbox.restore();
-  mongoose.connection.dropDatabase(done);
+  return mongoose.connection.dropDatabase();
 });
 
 export { sleep } from './sleep';