Optionally plot the DAC scans

Description

This aims at:

• improving the clarity of the options in gemos
• introduce the options not to plot the DAC scan results (now default)
• state in the warning for which VFATs the DAC scan fit fails

Related Issue

How Has This Been Tested?

Coffin setup

Types of changes

• 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)

Checklist:

• 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 read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.