feat: prepare for supporting buffer navigation and message loading

...main/java/de/justjanne/quasseldroid/QuasseldroidRouter.kt

.../java/de/justjanne/quasseldroid/messages/MessageBuffer.kt

...n/java/de/justjanne/quasseldroid/messages/MessageStore.kt

...de/justjanne/quasseldroid/service/ClientSessionWrapper.kt

.../java/de/justjanne/quasseldroid/service/QuasselBackend.kt

...n/java/de/justjanne/quasseldroid/service/QuasselBinder.kt

...n/java/de/justjanne/quasseldroid/service/QuasselRunner.kt

...stjanne/quasseldroid/ui/components/ConnectedClientCard.kt

...a/de/justjanne/quasseldroid/ui/components/CoreInfoView.kt

...java/de/justjanne/quasseldroid/ui/components/LoginView.kt

...justjanne/quasseldroid/ui/components/PasswordTextField.kt

...java/de/justjanne/quasseldroid/ui/routes/CoreInfoRoute.kt

...ain/java/de/justjanne/quasseldroid/ui/routes/HomeRoute.kt

...in/java/de/justjanne/quasseldroid/ui/routes/LoginRoute.kt

...ntion/src/main/kotlin/justjanne.kotlin.android.gradle.kts

...le/convention/src/main/kotlin/justjanne.kotlin.gradle.kts

gradle/libs.versions.toml