Backend Module: API to request all or selected backup types for backup size bar chart

[LHMoritz]

User story

1. As an enduser
2. I want to be able to filter the backup table and the backup bar chart in the frontend
3. So that I only see for me relevant backups filtered by the backup type.

Acceptance criteria

• Criterion 1: The backend module offers an API which provides backup information according to the requested backup types.
• Criterion 2: The API is capable of providing backup data for all existing backup types.

Definition of done (DoD)

• Github actions pipline: success / All test: success
• All acceptance criteria are met
• Code review done and approved
• Is merged to Dev branch
• Tests for new feature are implemented

DoD general criteria

• Feature has been fully implemented
• Feature has been merged into the mainline
• All acceptance criteria were met
• Product owner approved features
• All tests are passing
• Developers agreed to release