Add a shorthand for mapping from one object with similar fields

[zikani03]

When using DTOs it is common to have classes with similar fields, and it can get annoying real quick to have to type the getter calls on the source object even though gensett can generate the setter calls on the target.
Imagine we have

class User {
  String username;
  String address;
}

class UserDto {
  String username;
  String address;
}

And I want to write a hand-written mapper class or method

public static UserDto map(User user) {
 var dto = new UserDto(); 
 // dto:username,address
 // the line above is a gensett line which creates setters
 dto.setUsername(/* TODO: set me */);
 dto.setAddress(/* TODO: set me */);
}

Proposal:

Add a new shorthand and capability to the library to enable mapping from source to object.
target:<source>:field
target:setm:<source>:field

Where source is the other object

public static UserDto map(User user) {
 var dto = new UserDto();
  // the line below is a gensett line which creates setters
 // map:dto:user:username,address
 // setm:dto:user:username,address

 // the result shall be
 dto.setUsername(user.getUsername());
 dto.setAddress(user.getAddress());
}