Automatically set readOnly flag at fields without setter

[g-tom]

Consider a field accessible through getter method but with no setter:

public class HasReadOnlyField {
    private String readOnlyField;

    public String getReadOnlyField() {
        return this.readOnlyField;
    }
}

It could be useful to have such field automatically flagged readOnly, like it is the case for fields with the setter being annotated JsonbTransient.