Changes

[CImgPlugin] Add fetchable CImg and remove embedded cimg (#4357)

* support interface-type for auto_target_properties install macro

* try updating install macro

* try updating install macro again

* use (only) find_package for CImg

* fix image compilation for newer version of cimg

* remove cimg src

* export mutex symbol with a .def file for windows

* add comment

* add fetchable cimg

* fix packaging

* fix image_gui

* fix image_type comparison

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Co-authored-by: erik pernod <erik.pernod@gmail.com>