Dynamically reads header and templates in PDA format

Dynamically reads header and the number of dataset specified in the
header. Reads dynamically the template groups and templates samples in
PDA format (handles any number of group and/or samples in any order).

Formatting of metadata issues resolved.

Corrects issues:
guillaumeprevost/hiri-tardis-filter#1
guillaumeprevost/hiri-tardis-filter#2
guillaumeprevost/hiri-tardis-filter#3