Remove key unification on Section location references and rename for clarity

Summary of outcomes for Data Standard 3.2

• Problem Addressed: Unification between Location (with School ref) and LocationSchool (with School ref) on Section is currently automatic but in practice this is not always the case.
• High-level Reasoning: This will be a two-step process to fully fix. The first step is to remove the merge. This has been done in this ticket. The second is to rename one of the two elements so there is not a conflict in the database. The second change is breaking so only the first has been completed on this ticket. A separate ticket has been created to handle the rename, DATASTD-1368.
• Changes Made: Removed merge between Location and LocationSchool on Section.

Original ticket description follows:

Section has two references that offer a choice of describing location where a section takes place

• Section.Location (a Location, which is a School and a classroom identifier)
• Section.LocationSchool (a School)

If both are provided, then logically the School in both reference should be identical. However, in practice, as is evidenced by the Ed-Fi ODS API implementation (ODS-3082), this can cause some complexity when keys are unified.

So the recommendation is that this unification be dropped.

Also, the name "LocationSchool" is a bit misleading, as it is unclear if this is the host school who owns the section, or the physical location (see also the original report on ODS-3082). The recommendation is to change the name of LocationSchool to SiteLocationSchool to clarify that this is a physical building site and remove possible confusion. This also serves the ODS API database  implementation.