Update test data

[FerriolCalvet]

By looking at nf-core/fastquorum test datasets, I believe we could use those to also test deepUMIcaller

https://github.com/nf-core/fastquorum/blob/master/tests/pipeline/multi_fastq.nf.test
https://github.com/nf-core/test-datasets/tree/fastquorum/testdata/fastqs

We could either point directly to the two cases that are already uploaded to their pipeline repo, or we can set up some other way to get some files available via URL that could be provided directly as input for Nextflow.

Here is a list of cases that could be used for the testing:
https://www.ncbi.nlm.nih.gov/sra?term=SRP119013

(we could decide to also use one of these to test deepCSA downstream, but first we should check the number of mutations of some of these cases to make sure that it is a good testing scenario)

[FerriolCalvet]

all data downloaded and run, pending to add it as tests or decide if downsampling before that