Update [amo] to use v4 API, set custom cacheLengths (#7586)

* switch to v4 API

* set custom cacheLengths on amo badges

services/amo/amo-base.js

@@ -21,7 +21,7 @@ class BaseAmoService extends BaseJsonService {
   async fetch({ addonId }) {
     return this._requestJson({
       schema,
-      url: `https://addons.mozilla.org/api/v3/addons/addon/${addonId}/`,
+      url: `https://addons.mozilla.org/api/v4/addons/addon/${addonId}/`,
     })
   }
 }

services/amo/amo-downloads.service.js

@@ -24,6 +24,8 @@ class AmoWeeklyDownloads extends BaseAmoService {
     },
   ]
 
+  static _cacheLength = 21600
+
   static defaultBadgeData = { label: 'downloads' }
 
   static render({ downloads }) {

services/amo/amo-rating.service.js

@@ -23,6 +23,8 @@ export default class AmoRating extends BaseAmoService {
     },
   ]
 
+  static _cacheLength = 7200
+
   static render({ format, rating }) {
     rating = Math.round(rating)
     return {

services/amo/amo-users.service.js

@@ -14,6 +14,8 @@ export default class AmoUsers extends BaseAmoService {
     },
   ]
 
+  static _cacheLength = 21600
+
   static defaultBadgeData = { label: 'users' }
 
   static render({ users: downloads }) {