feat(exif): Enable EXIF Writing using FIMD_EXIF_RAW

[ProbablePrime]

FreeImage keeps two separate copies of Exif Metadata in memory:

• One is used/found in MDM_EXIF_MAIN and its extensions(e.g. MDM_EXIF_GPS).
• Another one is used when files are actually written that support the EXIF Format.
• In some cases you want to access, the raw data.
• A good example of this is when using MetadataModel.DestroyModel to wipe EXIF data on an image that you wanted persisted if that file is exported again from FreeImage.
• DestoryModel was also corrected to DestroyModel, this will result in a breaking change version but that's worth it!

With this you can use the following to clear and persist that "clearing" of the exif data on a FreeImage image:

ImageMetadata imageMetadata = new ImageMetadata(dib, true, true);
var model = imageMetadata[FREE_IMAGE_MDMODEL.FIMD_EXIF_RAW];
model.DestroyModel();

When you then write that subsequent image to a file, the file will not contain any EXIF data!

This is based on:

• https://sourceforge.net/p/freeimage/discussion/36111/thread/2d087f91/ where i discovered FIMD_EXIF_RAW
• https://sourceforge.net/p/freeimage/discussion/36111/thread/8233f5bc/ where I learnt how you might use it.

As this change doesn't touch the native library, you won't need to compile that again. This is a purely .NET change. -

[ProbablePrime]

Now a demo here: https://github.com/ProbablePrime/FreeImage-WipeExif/blob/main/Program.cs

[ProbablePrime]

While this is straight forward, I'm still wanting at least 1 team review from Geenz or Froox. Due to the nature of free-image being very complicated.

[Geenz]

Looks good to me.

[ProbablePrime]

Ok, I'll roll a new version thanks!, this unblocks some work im doing!

[ProbablePrime]

More context now available here: https://github.com/Yellow-Dog-Man/Resonite-Issues/issues/2015