FORMAT tags not in caps lock are not loaded in the genotype table

[SamuelNicaise]

Genotype fields whose name is not entirely in caps are not loaded in the database (so all values for those fields are None).

Per VCF 4.3 specification, FORMAT tag names match the regular expression ^[A-Za-z ][0-9A-Za-z .]*$

To Reproduce

1. Create a VCF with a FORMAT tag not entirely in caps lock
   ##FORMAT=<ID=VAF_min,Number=1,Type=Float,Description="VAF Variant Frequency minimum [Release=0.9.3;Date=20210721;AnnotationType=calculation]">

2. Create a new project with that VCF

3. Open the genotype module, see that all the genotype values for that field are None

5. Open the database with a SQLite viewer, see that all the values in the genotype table for that field are None

Note:

• This probably comes from this block in parse_variants() in the VcfReader class

      for gt_field in format_fields:
          try:
              value = sample[gt_field.upper()]
              if isinstance(value, list):
                  value = ",".join(str(i) for i in value)
              sample_data[gt_field] = value
          except AttributeError:
              pass