Backend/Analyisis Module: API's for new bar chart for storage overview page

[LHMoritz]

User story

1. As an enduser
2. I want a bar chart in the storage overview page
3. So that I can retrieve more detailed information about the composition of the backups.

Acceptance criteria

• Criterion 1: The backend module offers an api which provides the frontend with needed backup and task details for the selected timeframe.
• Criterion 2: The analyisis module provides the needed filter logic.

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