Get `VREF_ADC` values from the database

[lpetre-ulb]

Description

[See cms-gem-daq-project/vfatqc-python-scripts#288 for more details.]

This PR makes the following two changes:

• Don't filter out the vref_adc column from the database in getVFAT3CalInfo.
• Also fix an long standing misleading error message; even when all VFATs were found in the DB the following warning message was printed out:

Length of returned view does not match length of input vfat List
VFATs not found: []

Types of changes

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

Motivation and Context

DAC scan failures encountered during commissioning at P5.

How Has This Been Tested?

VREF_ADC values are correctly written to files in the $GEM_PATH and on the CTP7 with getCalInfoFromDB.py.

Checklist:

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

[jsturdy]

Does #263 also try to solve the same problem in a different way? Or is the problem #263 solves independent from the problem(s) addressed by this?

[lpetre-ulb]

This PR is not related to #263, but is a dependency of https://github.com/cms-gem-daq-project/vfatqc-python-scripts/pull/288. The vref_adc column was previously filtered out in getVFAT3CalInfo while its values are very important (as the past few days have shown ;)

The misleading warning message was also seen during debugging at P5, but is not the same as the one #263 is trying to fix.