SireBreed in Inseminations

[AndreasSchultzGEA]

Mtech (FN) would like to get the information about the primary breed of the used sire within an Insemination.
At the moment, they try to get it from the sireIdentifiers-Array.
A dedicated property for the primary breed of the used sire would be useful.
But: If there are more than one sire used, this may cause a problem.
A branch "PrimarySireBreed-in-Insemination" is prepared.

[cookeac]

We had a useful discussion on this. As with #564 there are potentially other ways to resolve this:

• Prefetch possible sires through the service-sires API (see service-sires API #402)
• Look up new sire identifiers when encountered using the service-sires API and a filter

We also noted that we are comfortable with adding primarySireBreed if this is the most efficient solution.

We also discussed the different semantic meanings of Sire Identifiers in this resource:

• If the sire is a natural mating, or no straw information is available, use the sireIdentifiers array in the main insemination resource
• If a semen straw was used and details are available, place the sire identifier in straw.sireIdentifiers
• If an embryo was implanted instead, place the sire identifier in embryo.sireIdentifiers and also populate the genetic dam.
  These should be documented for widespread understanding.