Finalize typesystem only when top level aggregate is ready

a UIMA AS service will finalize its typesystem incorrectly if
1. it is an AS-async-aggregate containing a colocated delegate which is itself an async aggregate, AND
2. the colocated async aggregate finishes initialization before one of the other top level delegates, AND
3. the late top level delegate has new types or new type priorities.

This can result in initialization errors if a type priority or AE initialization method references a missing
type or feature, or an exception later in process() doing the same.

The bug is caused because the typesystem is finalized when any colocated async aggregate finishes
initialization.