feat(settings): badge dictionaries that have updates

Report which sources have a newer file instead of a single flag, and
show a Material badge at the top-end corner of each such dictionary's
icon. The section icon carries the badge while the section is
collapsed.

app/src/main/java/com/example/research/DictionaryStatus.kt

@@ -7,7 +7,7 @@ sealed interface DictionaryStatus {
     data object Unknown : DictionaryStatus
     data object Checking : DictionaryStatus
     data object UpToDate : DictionaryStatus
-    data object NeedsUpdate : DictionaryStatus
+    data class NeedsUpdate(val sourceIds: Set<String>) : DictionaryStatus
     data object Empty : DictionaryStatus
     data class Error(val message: String) : DictionaryStatus
 }