Fix catpack on unbins and ignore catpack/summarise errors

[dialvarezs]

These are two fixes (kinda), both mentioned in #870

For the CAT_pack summarise error
More than a fix, this is a workaround, because this a limitation from CAT_pack side: MGXlab/CAT_pack#125

For the CAT_pack errors on unbinned data
The problem here was that when using catpack/contigs for the classification, we were passing it the split me make for publishing instead of the single file. This PR adds a concatenation step before that to prevent the error.

Closes #870.

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[jfy133]

Thanks @dialvarezs !