* Remove unnecessary load of /fg/css/client.css
* Replace dynamicLoader.loadStyles with dynamicLoader.loadStyle
* Replace Popup._injectStylesheet with dynamicLoader.loadStyle
* Remove unused global
* Rename PopupProxyHost to PopupFactory
* Update FrontendApiReceiver to support non-async handlers
* Make some functions non-async
* Make setCustomCss non-async
* Make setContentScale non-async
* Remove static
* Rename variables
* Pass frameId into PopupFactory's constructor
* Change FrontendApiReceiver source from popup-proxy-host to popup-factor
* Rename _invokeHostApi to _invoke
* Rename PopupProxy.getHostUrl to getUrl
* Create new logging methods on yomichan object
* Use new yomichan.logError instead of global logError
* Remove old logError
* Handle unhandledrejection events
* Add addEventListener stub
* Update log function
* Update error conversion to support more types
* Add log event
* Add API log function
* Log errors to the backend
* Make error/warning logs update the badge
* Clear log error indicator on extension button click
* Log correct URL on the background page
* Fix incorrect error conversion
* Remove unhandledrejection handling
Firefox doesn't support it properly.
* Remove unused argument type from log function
* Improve function name
* Change console.warn to yomichan.logWarning
* Move log forwarding initialization into main scripts
