Fully configure VFAT based on backend board files

Description

As described in #18 (closed), this MR aims at storing the full VFAT configuration on the back-end board. Once stored, the configuration file can be used to configure the VFAT in a completely controlled way.

The following breaking changes were introduction:

1. The configuration file is now named config_OHx_VFATy.cfg. This allows the legacy software to continue to work in parallel with the development software;
2. The first comment line has been dropped in favor of comments prefixed by #;
3. The VFAT register name must be "complete", i.e. everything which comes after GEM_AMC.OH.OHx.GEB.VFATy.. This allows the VFAT channel registers to also be set;

In addition, a commented configuration reference file has added to the repository.

Related Issue

Closes #18 (closed), and should help with #9 (closed).

How Has This Been Tested?

This MR has been tested on hardware; all the registers were set as described in the configuration files.

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.