Allow non-fixed allele ID MADC for some conversions

[alex-sandercock]

Currently, all conversions from MADC to VCF require a fixed allele ID MADC file. Though, it is not required if the user is only extracting the target loci and if they do not need/want the ref/alt allele information.

• So, the user should be able to use a raw MADC file in this instance, and
• They should be able to upload a .txt file that has three columns (TargetID, Chrom, Pos) to account for the potentially unique named target locus.

[alex-sandercock]

Updating the input file to also include an optional column for labeling the botloci marker (Y/N)