Fix KT-8091: J2K string with octal escaped chars

j2k/testData/fileOrElement/literalExpression/stringOctalChars.java

@@ -0,0 +1,7 @@
+public class A {
+    public String a = "\770123";
+    public String b = "\1110123";
+    public String c = "\3770123";
+    public String d = "\000Text";
+    public String f = "\09";
+}

j2k/testData/fileOrElement/literalExpression/stringOctalChars.kt

@@ -0,0 +1,7 @@
+class A {
+    var a = "\u003f0123"
+    var b = "\u00490123"
+    var c = "\u00ff0123"
+    var d = "\u0000Text"
+    var f = "\u00009"
+}