Create APIs for task list

[green-arrow]

Problem

We need to provide a way for the front end to access the task lists / tasks of a project. Ideally, we should be able to side load task lists + tasks from the projects API, as well as side load tasks from the task list API.

Subtasks

• Allow side-loading of task lists + tasks from project API
• Create task list API (allow side-loading of tasks from this API)
• Allow side loading of task list from tasks API

[joshsmith]

We discussed and for now are going to avoid side loading.

We'll want an endpoint for task-lists and one still for tasks. We may need to polish UI later to account for slow loading without blocking the UI rendering.

[joshsmith]

Closed by #557