Creating users or using nicknames

### Description
> Right now tasks are available for all users to view, help, edit, or even delete. This isn't very handy as this could be used wrongly.
### Solution
> Users (with passwords) or nicknames (passwords assigned to each task individually) should be used to protect tasks and save contribution of each user/nickname group. In the SubTasks, the status could be used to save the username or nickname of the device who finished that specific subtask, in order to make the contribution leaderboards and pie charts.