Incorrect count of READS in the WGS import wizard

[Nicklas Nordborg]

I discovered that the python code that is splitting a single FASTQ file into multiple files depending on flow cell id and lane has bug when counting the number of reads. It is missing the last read and the last file to be created is off by one and so is the total number of reads for all merged bioassays. The bug should be easy to fix, but it is not trivial to know which file that is the last one with an incorrect count so we probably have to check all current files and use a batch update to fix the incorrect values in the database.

[Nicklas Nordborg]

In 7576:

Fixes #1567: Incorrect count of READS in the WGS import wizard

Also added a check for an already exising FASTQ file which should never happen unless the reads in the FASTQ has been re-ordered.