optionally introduce local as var type since java 10 (IDEA-179176)

java/java-tests/testData/refactoring/introduceVariable/VarTypeExtractedJava10.after.java

@@ -0,0 +1,9 @@
+import java.util.*;
+class MyTest {
+    {
+        var temp = new ArrayList<String>();
+        foo(temp);
+    }
+
+    void foo(List<String> l) {}
+}

java/java-tests/testData/refactoring/introduceVariable/VarTypeExtractedJava10.java

@@ -0,0 +1,8 @@
+import java.util.*;
+class MyTest {
+    {
+        foo(<selection>new ArrayList<>()</selection>);
+    }
+
+    void foo(List<String> l) {}
+}