multi-sample lineage tasks

[dpark01]

Add multi-sample lineage calling support to tasks pangolin_many_samples and nextclade_many_samples in tasks_sarscov2.wdl. Update sarscov2_batch_relineage workflow to call multi-sample tasks instead of scattering across every genome. Update sarscov2_illumina_full to use sarscov2_batch_relineage instead of scattering sarscov2_lineages across every genome.

Do not merge yet: sarscov2_batch_relineage seems to be working okay so far, but sarscov2_illumina_full changes have not yet been vetted, esp with column order changes. Test run here. Check outputs with both GP teams before merge.