[ENA] For metagenomic assemblies the pipeline should inform users that ERZ accessions are just temporary

[mberacochea]

Description of feature

Maybe we shouldn't spit out the ERZ accession, but it's kind of the only accession at that point (when submitting an metagenomic assembly).

ENA docs:

As all assemblies in ENA are submitted as ‘analyses’, for each assembly submission, Webin will report a unique accession number that starts with ERZ. For most assemblies, this accession number is for internal processing only and will not be visible in the browser. As a result, for most assemblies you will receive additional post-processing accession numbers starting with GCA_.

    Always make a note of any accessions you receive as these are the unique identifiers for each of your submissions to ENA.

    The ERZ accession can be used to access information on the progress of the internal processing of each assembly through the [Webin Portal](https://ena-docs.readthedocs.io/en/latest/submit/general-guide/submissions-portal.html). You can also use this service to see the assigned chromosome, contig, and scaffold accessions. Please follow the Webin Portal link to learn more about this. See individual submission guidelines for information on what accessions you will receive for each assembly type.