Fix the vfatID array in the DAC scan analysis

[AndrewLevin]

The VFAT ID array is now passed through np.unique such it will only have 24 entries, one for each VFAT.

Description

Previously the VFAT ID array was thousands of entries long, because there is one entry in the DAC scan tree for each DAC value.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Motivation and Context

The commissioning team found that VFATs on different detectors appeared to have the same vfat ID.

How Has This Been Tested?

Yes, I ran over the DAC scan root file provided by @bregnery and got the expected output.

Screenshots (if appropriate):

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.