Round 2 of visual polish for Bugzilla Lite. I've attached my edits.

Thanks Amy So the clear icons as mentioned before will be missing until we use gaia-components which is being tracked in https://bugzilla.mozilla.org/show_bug.cgi?id=1141857 The rest of them I hopefully got done to spec, when you are testing again you will need to open the app, wait for it to load, kill the app via taskswitcher, then when you reload it should be updated. Fixed in https://github.com/mozilla-b2g/bzlite/commit/4d58c0eaad2685cf0e28b889cd1bed44e82cd688, cheers

Thanks Dale!