extract class: mutate static methods, fields imports ( IDEA-55588 )

java/java-tests/testData/refactoring/extractClass/staticImport/after/Extracted.java

@@ -0,0 +1,7 @@
+import java.util.Collections;
+
+public class Extracted {
+    static void foo() {
+        Collections.singletonList();
+    }
+}

java/java-tests/testData/refactoring/extractClass/staticImport/after/Test.java

@@ -0,0 +1,2 @@
+class Test {
+}

java/java-tests/testData/refactoring/extractClass/staticImport/before/Test.java

@@ -0,0 +1,6 @@
+import static java.util.Collections.singletonList;
+class Test {
+  static void foo(){
+     singletonList();
+  }
+}