PLT-2765 Limit username UI to 22 characters (#2918)

* Shortened username length to 22 characters

* Update user_settings_general.jsx

* Added username requirements to account settings page

* Switched to double quotes

to escape ' in JSX, must use double quotes

* Update en.json

* Update user_settings_general.jsx

* Update es.json

* Update fr.json

* Update ja.json

* Update pt.json

* Added missing {

webapp/utils/constants.jsx

@@ -634,7 +634,7 @@ export default {
     },
     OVERLAY_TIME_DELAY: 400,
     MIN_USERNAME_LENGTH: 3,
-    MAX_USERNAME_LENGTH: 64,
+    MAX_USERNAME_LENGTH: 22,
     MIN_PASSWORD_LENGTH: 5,
     MAX_PASSWORD_LENGTH: 50,
     TIME_SINCE_UPDATE_INTERVAL: 30000,