Fix: Move folderUID to alert group level

[ShivaniBanke]

Current State

The folder UID was being passed at the team config level, which forced all alerts to use the same folder as the global configuration. This limited the flexibility to organize alerts into different folders based on their purpose or team.

Changes

• Moved folderUid to the alert group level
• This allows different alert groups to be organized into different folders
• Maintained backward compatibility by falling back to team config if not specified

Notes

• This is a non-breaking change that will inherit folder UIDs from their parent alert group
• The team's default folder is still used as a fallback if not specified
• This change simplifies alert rule configuration by reducing redundancy