Define Nextflow workflow structure for the new Genome Compare pipeline

[JAlvarezJarreta]

Note: Child of Issue #9.

Requirements:

• The pipeline should be able to run in both LSF and SLURM
• The pipeline should request as input: a fasta file path, a GCA ID, a sequence JSON file and an output directory path
• The pipeline should generate the final report file in the given output directory
• The pipeline should be able to run several input tuples (fasta file + GCA + seq JSON) in parallel
• Optionally, these can be passed all inside a TSV/JSON/YAML file (choose the format you prefer), but the individual option should still be available
• Resources should be computed dynamically