FIR: refactor destructuring declaration building helpers

rename them since they generate variables with initialization, rather
than arbitrary statements, and this fact is used in scripts
and also add initialization helper, used for scripting support too.

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/DestructuringDeclaration.kt

@@ -10,7 +10,7 @@ import org.jetbrains.kotlin.fir.FirModuleData
 import org.jetbrains.kotlin.fir.builder.AbstractRawFirBuilder
 import org.jetbrains.kotlin.fir.builder.DestructuringContext
 import org.jetbrains.kotlin.fir.builder.FirAnnotationContainerBuilder
-import org.jetbrains.kotlin.fir.builder.addDestructuringStatements
+import org.jetbrains.kotlin.fir.builder.addDestructuringVariables
 import org.jetbrains.kotlin.fir.declarations.FirVariable
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
 import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
@@ -80,7 +80,7 @@ fun MutableList<FirStatement>.addDestructuringStatements(
     localEntries: Boolean,
 ) {
     with(DestructuringEntry) {
-        addDestructuringStatements(
+        addDestructuringVariables(
             moduleData,
             container,
             multiDeclaration.entries,