[DEV] Database integration

[harvestcore]

Summary: Integrate the project with a MongoDB engine.

In order to be able to create bots, commands, and other entities, it is necessary to integrate the software with a database.

Functional notes:

• The integration is only necessary for the backend project. The resources one contains only resources, and the worker project does not need to access data.

Technical notes:

• A service must be created so it is easy to inject the database connection anywhere in the project.
• DTO classes will be necessary to extend the functionality of the resources ones.
• The service must be generic, so all kinds of data can be managed.
• Keep the documentation in mind.
  • DB
  • Tools

Relates to:

• [US-01] Simplifying tasks through Discord bot commands #1
• [US-03] Expandable command set #5

Dependencies:

• [DEV] Configuration manager #30

Subtasks:

• None for now.

Acceptance criteria:

• Unit tests are added if possible.
• The technical notes are met.