AddOrUpdateAnnotationAttribute: Handle fully qualified enum values

[Jenson3210]

New functionalities

• Import and shorten fully qualified enum values

  // Before
  @Foo
  // After (with attributeValue="org.example.Values.ONE")
  import org.example.Values;
  @Foo(Values.ONE)

• Append class values to existing single-class annotations

  // Before
  @Foo(Integer.class)
  // After (with attributeValue="Long.class", appendArray=true)
  @Foo({Integer.class, Long.class})

Bug fixes

• Empty array handling with appendArray=true

  // Before
  @Foo(value = {})
  // Was producing: @Foo({, "hello"})
  // Now correctly: @Foo("hello")

• Attribute name vs value check in array updates

  // Was checking attributeValue instead of attributeName when updating arrays

• Comma-separated class values incorrectly matched as FQ class

  // "Integer.class,Long.class" was incorrectly treated as a single FQ class
  // Now correctly parsed as multiple class values

• Missing type info when appending FQ class values

  // Before
  @Foo(Integer.class)
  // After (with attributeValue="com.example.MyClass.class", appendArray=true)
  import com.example.MyClass;
  @Foo({Integer.class, MyClass.class})  // MyClass.class now has proper type info

[timtebeek]

Neat addition, thanks! Good to get more mileage out of this recipe with some bugs squashed to boot.