[minor] rename `this.styleSheets` to `this.assets` as we're also storing CSS [minor] added async script loader
[minor] rename `this.styleSheets` to `this.assets` as we're also storing CSS
[minor] added async script loader

bigpipe/bigpipe,tonybo2006/bigpipe,PatidarWeb/bigpipe,PatidarWeb/bigpipe,tonybo2006/bigpipe,bigpipe/bigpipe