API4KP — Synchronize IDL with UML Model

The IDL should be changed to match the UML model. This includes:
All sequences are defaulted to infinite range, but many should be [0..1]
Many structure fields have cardinality [1], but should be [0..1]
Most IDL sequences are not used and should be removed
All UML enumerated types should correspond to IDL as enumerated types
The UML model defines classes with attributes and no operations. They should instead be represented by a simple data structure with fields. If one of these non-behavioral classes uses inheritance; the resulting "subclass" data structure type should contain an additional field that has a type of the "superclass" type.

The IDL was resynchronized under the resolution to API4KP-19

While addressing the IDL was considered important to the FTF, it required the changes involved in API4KP-19 and thus has been addressed under that issue.