Add padding to ProgressBar
Remove Browser from inherting NSObject

This was originally added when trying to implement KVO oof the webView.
However that was needed and thus the change is reverted.
Remove unecessary changes

These changes were added previously when
attempting to implement KVO
Dynamic webView was not needed since were observing a property of webView
context not needed as well
add page load progress tracking

See https://bugzilla.mozilla.org/show_bug.cgi?id=1109647
Add animation for fading the bar after page loads
KVO properly updates progress bar