Refactor FAQ (#14372)

* refactor(faq): fetch from API on web
Also make question list more maintainable, allowing different questions across platforms

* fix(tests): don't return null when function is expected
Also removes the unnecessary default to web in controller

* fix(tests): add new fields to expectation, add placeholders

* refactor(faq): allow reordering

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

test/api/v4/faq/GET-faq.test.js

@@ -37,6 +37,8 @@ describe('GET /faq', () => {
 
       expect(res).to.have.property('questions');
       expect(res.questions[0]).to.eql({
+        exclusions: [],
+        heading: 'overview',
         question: translate('faqQuestion0'),
         ios: translate('iosFaqAnswer0'),
       });
@@ -57,6 +59,8 @@ describe('GET /faq', () => {
 
       expect(res).to.have.property('questions');
       expect(res.questions[0]).to.eql({
+        exclusions: [],
+        heading: 'overview',
         question: translate('faqQuestion0'),
         android: translate('androidFaqAnswer0'),
       });