fix: Make CtField inherit from CtResource

Fields are allowed in try-with-resources statements now, so spoon should
model this case.

src/main/java/spoon/reflect/declaration/CtField.java

@@ -9,14 +9,15 @@
 
 import spoon.reflect.code.CtExpression;
 import spoon.reflect.code.CtRHSReceiver;
+import spoon.reflect.code.CtResource;
 import spoon.reflect.reference.CtFieldReference;
 import spoon.support.DerivedProperty;
 import spoon.support.UnsettableProperty;
 
 /**
  * This element defines a field declaration.
  */
-public interface CtField<T> extends CtVariable<T>, CtTypeMember, CtRHSReceiver<T>, CtShadowable {
+public interface CtField<T> extends CtVariable<T>, CtResource<T>, CtTypeMember, CtRHSReceiver<T>, CtShadowable {
 
 	/**
 	 * The separator for a string representation of a field.