Task Management Backend

[StInvestigator]

As a user, I want to manage tasks so that I can organize my work.

Tasks

1. [Task Management Backend] Create Task Entity #40
2. [Task Management Backend] Create Task Repository #41
3. [Task Management Backend] Create Task Service #42
4. [Task Management Backend] Create Task DTOs #43
5. [Task Management Backend] Create Task Mapper #44
6. [Task Management Backend] Create Task Controller #45
7. [Task Management Backend] Implement Collaborator Management #46