PerformanceEvaluation data model index update and new `status` field

We are using the PeformanceEvaluation data tables (and other related tables) to store Observations and Evaluations. However, we have encountered two limitations with the data model:

1. Missing "status" field

**Observations in our system can take on different "statuses" (i.e. 'in progress', 'complete', 'draft'). We can not see any valid field to store this, and it seems like a good inclusion to add alongside the "Grade" and "Subject" fields that exist already. The main problem we have now is not being able to create status reports using data in the ODS.

2. Index is too narrow

As a background, teachers can be observed (evaluated) in our system any number of times throughout the year, and we support multiple observations on the same day for the same teacher.

The index/identity on the `PerformanceEvaluation` table contains the following six fields: EvaluationTitle, EdFi.Term, and PerformanceEvaluationType, EdFI.SchoolYear, EvaluationPeriod, and EdFi.EducationOrganization. We're using this in conjunction with `PerformanceEvaluationRating` to store multiple ratings for an observation. However, the identity fields on `PerformanceEvaluation` prevent us from being able to store more than 1 observation for a teacher in an academic period.

To get around this, we have had to prepend our unique identifier for the observation (i.e. evaluation) to the EvaluationTitle field, allowing us to store multiple observations for each teacher/academic period. For example, this looks like "186539 - Informal Classroom Walkthrough".

One suggestion we have is to update the index/identity of the `PerformanceEvaluation` domain entity to include the teacher (EdFi.Person), date (ActualDate) and probably also a time (ActualTime). This would ensure that we could create multiple records for a teacher without having to prepend the ID to the title to make the row unique.

Thank you very much as always for your time and consideration, and please let me know if you would like or need any additional info from me.