Delete macro APIs, update DataClass example macro, add script to run it (#2086)

- The macro apis now live in the SDK, so delete them from here and update the links.
- Update the DataClass macro style a bit, and migrate to the latest API.
- Add a script to actually run the DataClass macro on a fake class, logs some timing information and the resulting augmentation library.

Author: jakemac53

analysis_options.yaml

@@ -1,5 +1,3 @@
 analyzer:
   exclude:
     - accepted/2.3/spread-collections/examples/**
-    # Uses not-yet-existing language features
-    - working/macros/example/**