[FEATURE] @JsonSetter annotation should be copied to builder's setter method

[dlutz]

Describe the feature
Jackson's @JsonSetter annotation set on a field should be copied to the builder's corresponding setter method, similar to the jackson annotation @JsonProperty (see #1981).

Example Java class:

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonSetter;
import com.fasterxml.jackson.annotation.Nulls;

import lombok.Builder;
import lombok.Setter;

@Builder
public class JacksonJsonSetter {
  @JsonProperty("some-attribute")
  @JsonSetter(nulls = Nulls.SKIP)
  @Setter
  @Builder.Default public String someAttribute = "default-value";
}

(I added @JsonProperty to show the similarity.)

This should produce something like this:

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonSetter;
import com.fasterxml.jackson.annotation.Nulls;

public class JacksonJsonSetter {
  @JsonProperty("some-attribute")
  @JsonSetter(nulls = Nulls.SKIP)
  public String someAttribute;

  @java.lang.SuppressWarnings("all")
  @lombok.Generated
  private static String $default$someAttribute() {
    return "default-value";
  }

  @java.lang.SuppressWarnings("all")
  @lombok.Generated
  JacksonJsonSetter(final String someAttribute) {
    this.someAttribute = someAttribute;
  }


  @java.lang.SuppressWarnings("all")
  @lombok.Generated
  public static class JacksonJsonSetterBuilder {
    @java.lang.SuppressWarnings("all")
    @lombok.Generated
    private boolean someAttribute$set;
    @java.lang.SuppressWarnings("all")
    @lombok.Generated
    private String someAttribute;

    @java.lang.SuppressWarnings("all")
    @lombok.Generated
    JacksonJsonSetterBuilder() {
    }

    @JsonProperty("some-attribute")
    @JsonSetter(nulls = Nulls.SKIP)
    @java.lang.SuppressWarnings("all")
    @lombok.Generated
    public JacksonJsonSetterBuilder someAttribute(final String someAttribute) {
      this.someAttribute = someAttribute;
      someAttribute$set = true;
      return this;
    }

    @java.lang.SuppressWarnings("all")
    @lombok.Generated
    public JacksonJsonSetter build() {
      String someAttribute = this.someAttribute;
      if (!someAttribute$set) someAttribute = JacksonJsonSetter.$default$someAttribute();
      return new JacksonJsonSetter(someAttribute);
    }

    @java.lang.Override
    @java.lang.SuppressWarnings("all")
    @lombok.Generated
    public java.lang.String toString() {
      return "JacksonJsonSetter.JacksonJsonSetterBuilder(someAttribute=" + this.someAttribute + ")";
    }
  }

  @java.lang.SuppressWarnings("all")
  @lombok.Generated
  public static JacksonJsonSetterBuilder builder() {
    return new JacksonJsonSetterBuilder();
  }

  @JsonProperty("some-attribute")
  @JsonSetter(nulls = Nulls.SKIP)
  @java.lang.SuppressWarnings("all")
  @lombok.Generated
  public void setSomeAttribute(final String someAttribute) {
    this.someAttribute = someAttribute;
  }
}

Describe the target audience
People wanting to use the @JsonSetter annotation to influence the deserialization of some JSON attributes.

In my project, I wanted to use @JsonSetter(nulls = Nulls.SKIP) to force setting a default value if the field is set to null in the JSON input. I needed to manually add the annotation to the setters by using an interface, as recommended on @Builder / With Jackson. If this annotation was copied to the builder's setter methods, I could avoid the additional code in this interface.