Annotations (birds-eye view)

Based on the email exchange between @tijmenbaarda and Jeroen Salman on November 18-19:

- Annotations may take three forms.
1. Correcting a field's value.
2. Adding a missing field.
3. General comment to the record as a whole.
- Annotations are specific to the project but not to the collection. All collections within a project see the same annotations.
- It must be possible for two different users to make separate (potentially even conflicting) annotations on the same field of the same record within the same project.
- When a field has multiple values (or can have multiple values), it must be possible to annotate (i.e., correct or add) each value separately.

Regarding the latter point, it is probably helpful to think not of a field with multiple values, but of multiple field-value pairs that happen to have the same field type.