Intercropping: Support multiple accessions per plot

[dwaring87]

We've been storing some oat/pea intercropping trials where each plot has an oat accession and a pea accession in it. For now, we've been adding which pea variety is in each plot as a management factor. We'd like to be able to directly link more than one Accession entry to a plot.

Requirements:

• Ability to have more than one species of Accessions (already works)

  • add intercrop accessions to the database with the correct species_name set
  • accession names need to be unique across species? Would it be useful to have the ability to use the same name in different species? Or would this just create more problems?

• Ability to have more than one Accession per plot

  • modify trial upload template to include additional accessions per plot
  • modify UI on website to display additional accessions
  • modify data downloads to include additional accessions
  • modify BrAPI requests to include additional accessions <-- this will need a change to the BrAPI spec