Fixed containingDeclaration for descriptors inside init-blocks for the case of no primary constructor

KT-10226 Wrong Imports optimization ("Unresolved reference" is being added)

 #KT-10226 Fixed

idea/testData/editor/optimizeImports/KT10226.kt

@@ -0,0 +1,10 @@
+import java.io.File
+
+class C {
+    constructor(file: File)
+
+    init {
+        val xxx = 1
+        xxx.inc()
+    }
+}

idea/testData/editor/optimizeImports/KT10226.kt.after

@@ -0,0 +1,10 @@
+import java.io.File
+
+class C {
+    constructor(file: File)
+
+    init {
+        val xxx = 1
+        xxx.inc()
+    }
+}