Cleanup VersionedIPreparedModel and PreparedModelCallback

This CL changes VersionedIPreparedModel to be synchronous. It returns
the results by value instead of requiring a callback be passed in.
Additionally, the IPreparedModel is wrapped in VersionedIPreparedModel
before being returned.

This CL additionally simplifies PreparedModelCallback by (1) decoupling
it from the base, (2) removing functions that are not used.

Bug: 118624080
Test: mma
Test: atest NeuralNetworksTest_static
Test: atest VtsHalNeuralnetworksV1_0TargetTest (with sample-all)
Test: atest VtsHalNeuralnetworksV1_1TargetTest (with sample-all)
Test: atest VtsHalNeuralnetworksV1_2TargetTest (with sample-all)
Change-Id: Ic7587e0680ca7ccdc6cf429d9537396540ab3c0d
(cherry picked from commit b2584cdb9b275c9c3e876e0c895b09937e066a6e)