Replace KirigamiAddons.Banner with Kirigami.InlineMessage
Now it supports all the use cases that Banner did. This was the only thing using KirigamiAddons in the app, so now we can remove that dependency.
The InlineMessage changes are in KF 6.0 such that we can get this change into Plasma 6, right? I know we're past the dependency freeze, but my understanding is that removing dependencies is fine, you just can't add new ones.