Add task and project searching

[pawelgrimm]

Acceptance criteria:

• The task and project fields can be used to search for existing tasks/projects
• if an existing task/project is selected, that task/project is associated with the session
• if a new task/project is selected, a corresponding row is created in the tasks/projects table and linked to the session

Note:
Use https://fusejs.io/a to set up client-side searching