fix: Clean up out-of-scope references to auto-managed resource

[slarse]

Fix #561

This PR makes the UnclosedResourcesProcessor clean up references to the variable that was inlined into the resource block. Previously, such left-over references were not cleaned up, causing compile errors.

Here's an example of the new-and-improved repair, note how it removes the if in the catcher:

 public class ReferenceInCatcherAndFinalizerToFieldWithSameNameAsResource {
     private int bw = 2;

     public void saveTo(File file) throws IOException {
-        BufferedWriter bw = null;
-        try {
-            bw = new BufferedWriter(new FileWriter(file)); // Noncompliant
+        try (BufferedWriter bw = new BufferedWriter(new FileWriter(file))) {
             bw.write("Write some stuff to file");
         } catch (IOException e) {
             e.printStackTrace();
             System.out.println(this.bw); // reference to field; should not be cleaned!
-            if (bw != null) { // reference to local variable; should be cleaned!
-                bw.close(); // reference to local variable; should be cleaned!
-            }
         } finally {
             System.out.println(this.bw); // reference to field; should not be cleaned!
             System.out.println("done");

         }
     }
 }

It works by looking for references to the inlined variable inside the catchers and finalizer, and removing any statement containing a reference. It's possible that this could "over clean" for example by removing an if statement where the condition has a reference to the resource, but there's also unrelated stuff inside of the then or else blocks. But I think we'll deal with that only if we actually find it happening, as I've said before, this processor will never be perfect.

[fermadeiral]

LGTM.