[browser] Avoid toolbar button offset while loading. Fixes JB#48356
[browser] Avoid toolbar button offset while loading. Fixes JB#48356

Regression on commit 31edc522b560, switching hiding to active
property makes it fade in/out too.

Also adjusted some minor details while at it.

sailfishos/sailfish-browser,sailfishos/sailfish-browser,sailfishos/sailfish-browser,sailfishos/sailfish-browser,sailfishos/sailfish-browser