Workday: display project name under the task title

Summary:
Implementation details:

• QueryTreeModel and QueryTreeNode have a new template parameter AdditionalInfo
• QueryTreeModel fetches additional info on demand and stores it into the node
• WorkdayPageModel uses m_taskQueries->findProject() as AdditionalInfo

This can be extended later to store a context query as well.

Reviewers: ervin

Reviewed By: ervin

Subscribers: Zanshin

Differential Revision: https://phabricator.kde.org/D16036