* Use colors from palette; with this the custom scrollbars should always
be a plus (and not only when the Breeze style is used)
* React to palette changes at runtime
* The code is disabled under many platforms where the Breeze style is
unlikely to be used anyways.
* The code is disabled if Qt is older than 6.1 because only then the name
of the current style can be determined.
This makes the code simpler and avoids inconsistent spacing. Unfortunately
this function has only been introduced in Qt 6.4 so the old code has to
stay for older Qt versions.
* Remember new size after user resized the window
* Remember new position after user repositioned window and using explicit
coordinates has been configured in the appearance settings
Not sure why I'm getting
```
Fehler beim Abfragen der Syncthing-Konfiguration: Error transferring http://127.0.0.1:8384/rest/system/config - server replied: Forbidden
URL der Anfrage: http://127.0.0.1:8384/rest/system/config
```
one one of my setups but this kind of error can likely be ignored shortly
after the start similar to other types of errors.
Apparently this is still problematic leading to errors like
`Qualifying with unknown namespace/class`. It seems that moving the enum to
a different header file works. The trick to use a macro to define
`enum class` ceased to work on the other hand.
Specifying a function with the namespace like
`void QtGui::FinalWizardPage::showResults()` leads to the same problem and
also needs to be avoided.
* Do not blindly override existing auto start entry
* Warn if an auto start entry exists but points to a different executable
* Allow removing such an entry explicitly
This is now misleading as it depends on the general web settings. The
presence of this new settings tab alone should make it clear what will
happen instead so the sentence can just be dropped.