Add support for shared builds on windows

[thesn10]

In this PR i have added support for shared linking on windows.
This is helpful if you need seperate .dll files, for example avformat.dll or other libraries

You can append -shared to the version to enable it:

with:
  ffmpeg-version: '5.1.1-shared'
  # or
  ffmpeg-version: 'release-shared'

This will make it download the shared build with seperate .dll files like this:

> dir C:\hostedtoolcache\windows\ffmpeg\6.1.1\x64

Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a---          12/31/2023  8:23 AM       79826944 avcodec-60.dll
-a---          12/31/2023  8:23 AM        4417024 avdevice-60.dll
-a---          12/31/2023  8:23 AM       39759872 avfilter-9.dll
-a---          12/31/2023  8:23 AM       17132544 avformat-60.dll
-a---          12/31/2023  8:23 AM        2302976 avutil-58.dll
-a---          12/31/2023  8:23 AM         388608 ffmpeg.exe
-a---          12/31/2023  8:23 AM        1875968 ffplay.exe
-a---          12/31/2023  8:23 AM         192000 ffprobe.exe
-a---          12/31/2023  8:23 AM          76288 postproc-57.dll
-a---          12/31/2023  8:23 AM         436224 swresample-4.dll
-a---          12/31/2023  8:23 AM         643072 swscale-7.dll

[federicocarboni]

Instead of adding a suffix to ffmpeg-version I'd rather use a new input (something like linking which could be static or shared) and error out when set to shared on macos or linux. The functionality itself looks good though 👍

[thesn10]

Yes that is a good idea, i'm going to implement it

[thesn10]

I have added the linking-type option

[federicocarboni]

Everything looks good 👍