Add "Manager" as a field for the Atlassian Accounts profile

Problem Definition

For some companies, the Manager of a user is important information to be displayed at the users' profile.

Suggested Solutions

Add this as an Atlassian Account field so that the users can start using that.

side note: this would also help companies that user user provisioning integration as some Identity Providers already map this field to the users' profile. On the other hand, that field is still not working for the integration yet (here is another feature request to include it).