Initial work on AUv3 support

[kunitoki]

No description provided.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.23%. Comparing base (7f9f519) to head (adfbe16).
⚠️ Report is 2 commits behind head on dev/windows_work_aax.

Additional details and impacted files

@@                  Coverage Diff                  @@
##           dev/windows_work_aax     #125   +/-   ##
=====================================================
  Coverage                 79.22%   79.23%           
=====================================================
  Files                       681      681           
  Lines                     67361    67366    +5     
=====================================================
+ Hits                      53370    53375    +5     
  Misses                    13991    13991           

Files with missing lines	Coverage Δ
...udio_plugin_host/host/yup_AudioPluginDescription.h	100.00% <100.00%> (ø)
...dio_processors/processors/yup_AudioProcessorBase.h	92.68% <ø> (ø)

... and 4 files with indirect coverage changes

---

Continue to review full report in Codecov by Harness.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7f9f519...adfbe16. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.