Use resampler library

[norihiro]

Description

Instead of adding or removing one frame, use resampler so that the added or removed frames are not noticed as a noise.

Fix #1.

How Has This Been Tested?

General checklist

• The commit is reviewed by yourself.
• The code is tested.
• Document is up to date or not necessary to be changed.
• The commit is compatible with repository's license.

[norihiro]

This does not work on macOS.
Version strings in the library should be omitted. Currently, otool -L shows as below.

obs-async-audio-filter.plugin/Contents/MacOS/obs-async-audio-filter (architecture x86_64):
	@rpath/libobs.framework/Versions/A/libobs (compatibility version 1.0.0, current version 28.0.0)
	@rpath/libswresample.4.3.100.dylib (compatibility version 4.0.0, current version 4.3.100)
	@rpath/libavutil.57.17.100.dylib (compatibility version 57.0.0, current version 57.17.100)

[norihiro]

This also does not work on Windows.
The DLL requires swresample-3.dll but OBS 30.0 provides swresample-4.dll.

[norihiro]

Relying on DLLs from OBS Studio would confuse users when they update OBS Studio.
I will re-write the implementation to use a static-linked library.