Fix disappearance items when fast scrolling (#1035)

* Don't use animateItem's fade-in/fade-out in FastScrollLazyColumn

* Move to extension function

Avoid using animateItemPlacement name since it's shadowed by compose-bom's deprecated one

app/src/main/java/eu/kanade/presentation/util/FastScrollAnimateItem.kt

@@ -0,0 +1,8 @@
+package eu.kanade.presentation.util
+
+import androidx.compose.foundation.lazy.LazyItemScope
+import androidx.compose.ui.Modifier
+
+// https://issuetracker.google.com/352584409
+context(LazyItemScope)
+fun Modifier.animateItemFastScroll() = this.animateItem(fadeInSpec = null, fadeOutSpec = null)