Change source code map setting in webpack

[mymindstorm]

As of the latest release, file sizes in dist are:

76K	argon.js
200K	argon.js.map
896K	background.js
3.2M	background.js.map
48K	content.js
60K	content.js.map
960K	import.js
3.6M	import.js.map
80K	options.js
380K	options.js.map
956K	popup.js
3.5M	popup.js.map
4.0K	qrdebug.js
12K	qrdebug.js.map

It seems a bit unnecessary to keep ~10M worth of source maps in a production version. We should investigate different source map types.

[WAZAAAAA0]

problem persists

just for reference, I have 72 .xpi files in my Firefox extensions folder, and Authenticator is the 3rd biggest, only behind:

• Augmented Steam, which does the same mistake of bundling source maps into the release
• LocalCDN, which is excused because it has to bundle hundreds of javascript frameworks to do its work