Use optional chaining more in the `src/display/network.js` file
Use optional chaining more in the `src/display/network.js` file

Also changes the different `_onDone`/`_onProgress` methods to use consistent parameter names, and some other small improvements.

Shoobx/pdf.js,macroplant/pdf.js,Shoobx/pdf.js,nawawi/pdf.js,mozilla/pdf.js,showpad/mozilla-pdf.js,showpad/mozilla-pdf.js,xavier114fch/pdf.js,Snuffleupagus/pdf.js,showpad/mozilla-pdf.js,xavier114fch/pdf.js,timvandermeij/pdf.js,Snuffleupagus/pdf.js,timvandermeij/pdf.js,nawawi/pdf.js,macroplant/pdf.js,macroplant/pdf.js,mozilla/pdf.js,Shoobx/pdf.js,Snuffleupagus/pdf.js,mozilla/pdf.js,nawawi/pdf.js,timvandermeij/pdf.js