Prefer Firefox over Chrome

After #374 we don't need webviz certificate --auto-install anymore.
Switching the preferred browser to firefox, unless overruled by webviz preferences, will make the conversion on localhost smoother, as no actions are required by the end user due to the certificate change.

webviz-config/webviz_config/utils/_localhost_open_browser.py

Lines 59 to 63 in ee4b403

    
           for browser in ["chrome", "chromium-browser"]: 
        
               try: 
        
                   return webbrowser.get(using=browser) 
        
               except webbrowser.Error: 
        
                   pass

I'll think about whether it's possible to solve #288 instead. We'd rather use the user's default browser unless it's too old, in which case we provide eg. Firefox. This isn't something that's possible to do via the webbrowser module since it's a bit dumb, but could perhaps be possible with some extra Python code.

@dotfloat 👍 Think we'll have to do at least one of them before the next release to make the transition as smooth as possible.
But to add Firefox as preferred is of course super simple, so can wait until we are close to feature freeze.

I agree. We could probably just do Firefox now and then later on do #288.

	for browser in ["chrome", "chromium-browser"]:
	try:
	return webbrowser.get(using=browser)
	except webbrowser.Error:
	pass