Datasource v2 reads metadata twice

[guykhazma]

Need to verify if when using datasource v2 the metadata is being read twice.
This is currently handled in the tests by multiplying by 2 the number of files expected to be skipped.
see:

xskipper/src/test/scala/io/xskipper/testing/util/Utils.scala

Line 134 in 363408c

// return the number of skipped files to compare with the actual number