refactor: make all fields in CompositionComponent to non-nullable

Author: goofyz

app/src/main/java/com/osfans/trime/data/theme/model/CompositionComponent.kt

@@ -2,15 +2,15 @@ package com.osfans.trime.data.theme.model
 
 data class CompositionComponent(
     val start: String,
-    val move: String?,
+    val move: String,
     val end: String,
-    val composition: String?,
-    val letterSpacing: Int?,
-    val label: String?,
-    val candidate: String?,
-    val comment: String?,
-    val sep: String?,
-    val align: String?,
-    val whenStr: String?,
+    val composition: String,
+    val letterSpacing: Int,
+    val label: String,
+    val candidate: String,
+    val comment: String,
+    val sep: String,
+    val align: String,
+    val whenStr: String,
     val click: String,
 )