Add user first name and last name fields to Get User API response

Currently Aha stores user first and last names. In the get user and list users REST API response objects, those fields are combined into one field: name. So John and Doe just get returned as John Doe. This causes problems when you have many different cultural names where it is impossible to parse the name into first and last names. In one case, the name field contains 5 different names, where the user's first name is the first three and their last name is the last two. In another case, of the four names, only the last 'R' is the last name. This is very important when you need to identify users in LDAP and can't rely on searching by their email addresses because of over 14 different email suffixes in use due to mergers and acquisitions.