FFmpegKit Flutter v4.5.1

• Based on FFmpegKit native v4.5.1 releases
• Includes FFmpeg v4.5-dev-3393
• Switches to shared/dynamic libraries on iOS
• API Changes
  • Implements execute() methods
  • Replaces ExecuteCallback with session specific CompleteCallback types (FFmpegSessionCompleteCallback, FFprobeSessionCompleteCallback, MediaInformationSessionCompleteCallback)
  • saf protocol urls created by FFmpegKit.getSafParameter methods are no longer single-use. They can be re-used multiple times
  • New FFmpegKit.getSafParameter method that allows providing a custom open mode
  • Implements chapters in MediaInformation class
• Adds support for zimg library (enables zscale filter)
• Enables 10bit pixel formats in x265
• Uses the new versions of fontconfig, freetype, fribidi, kvazaar, libvpx and x264
• Fixes issues #209, #221 and #224

Tested using v4.5.1 test applications