Contributor creation/edition form should allow to create or update contributor entity by entering full name

@antongp Do you have an idea of how you would like to do this? How would we know what parts (Leading initial, Prefix, First name, Middle name, Last name, Nickname, Suffix) the user entered? If you have ideas, I'd be happy to work on this.

It seems like this might be a lot easier (and admittedly much different from the goal of this issue) to display the parts of a name, like with the https://www.drupal.org/project/realname module.