Imports are not part of the visited Spoon AST

### Describe the bug

I tried to access the import element through the ctimport filter, but it wasn't available

### Source code you are trying to analyze/transform

```Java
package src.p4;

import src.p1.A;

import java.util.Date;

public class E implements D {
public static int e = 5;
protected final int d = 4;
int a = 1;
private final int c = 3;

public E() {
System.out.println("this is a constructor!");
}

@Override
public void fun1() {
// test fun1
int b = 2;
System.out.println("global:" + a);
System.out.println("local:" + b);
}

@Override
public void fun3() {
Date date = new Date();
A a1 = new A();
a1.m1();
long time = date.getTime();
System.out.println("time:" + time);
}

public final void fun2() {
System.out.println("final fun!!");
}
}
```

### Source code for your Spoon processing

```Java
Launcher launcher = new Launcher();
launcher.getEnvironment().setComplianceLevel(11);
launcher.getEnvironment().setAutoImports(true);
launcher.addInputResource("D:\\test\\FILE_STORY\\java\\javademo2\\src\\p4\\E.java");
CtModel model = launcher.buildModel();

List imports = model.getElements(new TypeFilter<>(CtImport.class));
System.out.println("size:"+imports.size());
```

### Actual output

```Java
size:0
```

### Expected output

```Java
size:2
```

### Spoon Version

10.3.0

### JVM Version

11

### What operating system are you using?

win10