Adds support for audio capture-effect enumeration on Windows - part 2

Contains additional changes and improvements proposed after landing
by robliao@.

Bug: 1133643
Change-Id: Ib05e3878b70fc10fa5255645d4551639e2c96587
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2514423


Commit-Queue: Henrik Andreasson <henrika@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823252}