[WIP] Feature/tenants repo init

[mar-be]

When the tenant repository is initialized, all existing files are copied to the default tenant.

• [ ] Ensure that you followed our toolchain guide.
• [ ] Branch name checked. That means, the branch name starts with thesis/, fix/, ...
• [ ] Ensure that the commit message is a good commit message
• [ ] Ensure to use auto format in all files
• [ ] Ensure that you appear in NOTICE at Copyright Holders
• [ ] Tests created for changes
• [ ] Documentation updated (if needed)
• [ ] Screenshots added (for UI changes)