HTTP endpoint to list tasks

Create HTTP endpoint to return JSON list of tasks.

For example:

GET /v1/tasks

{
  "tasks":[...]
}

The endpoint may support filters to retrieve tasks by different fields:

• GET /v1/tasks?name=didResolve - return all did resolve tasks
• GET /v1/tasks?state=pending - return all pending tasks
• GET /v1/tasks?state=done&name=didResolve - return all did resolve tasks which are completed