Fix: Use correct After-queryParam when none specified

[GODrums]

Motivation

Fixes an issue where the after param is after the before param due to the week starting on Tuesdays. I.e. https://hephaestus.ase.cit.tum.de redirects to https://hephaestus.ase.cit.tum.de/?after=2024-11-26T09:00:00%2B01:00&before=2024-11-25T00:22:47%2B01:00 right now, making the default leaderboard data incorrect.

Description

This fix moves the default date configuration to the leaderboard filter component, making sure dates are only changed in one place of the application.
Also fixes a small bug regarding the recently merged PR #124, where the default value of the Team-Color-Input had an invalid default value:

Testing Instructions

• Run application-server and webapp
• Go to http://localhost:4200/ and check if the default leaderboard uses the correct timeframe.

Screenshots (if applicable)

Checklist

General

• PR title is clear and descriptive
• PR description explains the purpose and changes
• Code follows project coding standards
• Self-review of the code has been done
• Changes have been tested locally
• Screenshots have been attached (if applicable)
• Documentation has been updated (if applicable)