Update chaoscenter server to allow further customization of default ChaosHub

[Calvinaud]

• Update Configuration to read new environment variables
• Update listDefaultHubs function to include new parameters for the default chaoshub
• Update SyncDefaultChaosHubs to retrieve the new parameters from listDefaultHubs

Proposed changes

The PR allow to use others environment variables to configurate the default ChaosHub which will allow to update the name and use private repository for the default ChaosHub.

#5063

Types of changes

What types of changes does your code introduce to Litmus? Put an x in the boxes that apply

• New feature (non-breaking change which adds functionality)
• Bugfix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices applies)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• I have read the CONTRIBUTING doc
• I have signed the commit for DCO to be passed.
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if appropriate)
• I have added necessary documentation (if appropriate)

[Calvinaud]

CIFuzz / Fuzzing (address) (pull_request) seem to failing due to artifact action version that will be fixed by: #5050

[amityt]

Awesome! 🚀