add rank as a title property

[hypnopotamus]

https://xd.adobe.com/view/606b2df3-94c5-4190-a864-2a58fc44ffad-3538/screen/3c78f506-c9ff-4d16-8592-ff500fc8ac85

• Add a Rank type to the domain model
• seed rank with the three values Junior, Senior, Director
• add a Rank property to a Title
• seed Titles to be linked to the right rank
• update the Title contract type to have a rank: string property
• update the comparison page to be able to reconstruct the domain model from the ReST API response