Fix set of GZ_SIM_RESOURCE_PATH in tests on Windows

[traversaro]

I was trying to get the tests on Windows to work, and I noticed that the modifications in https://github.com/robotology/gz-sim-yarp-plugins/pull/176/files were unix-specific, as they used : as separator for env variables that contain list of paths, while on Windows ; is used (as : could be ambigous with the driver letter separator, i.e. the lists on Windows are C:\src;C:\otherdir, not C:\src:C:\otherdir that would be ambiguous.

To fix this, I modified the CMake to use ENVIRONMENT_MODIFICATION and path_list_append command, that handles this differences between Windows and *nix automatically, see https://cmake.org/cmake/help/latest/prop_test/ENVIRONMENT_MODIFICATION.html .

To do so, I bumped the minimum CMake version to 3.22 .

Furthermore, I also added .Finalize() calls to all the fixtures that were missing them, to get rid of the "[Wrn] [D:\bld\gz-sim8_1713968558858\work\src\TestFixture.cc:208] Fixture has not been finalized, any functions you attemptedto hook into will not be run. It is recommended to call Finalize()before accessing the server. warnings.

I also removed the LIBGL_ALWAYS_SOFTWARE=1, as they are not necessary since gazebosim/gz-sim#920 has been fixed.

Fix #181 .

[traversaro]

(there is a spurious commit, please squash and merge).

[traversaro]

Even with this fix, the test still segfault on Windows, but I will investigate this once all the PR of fixes are merged.

[xela-95]

Thanks a lot @traversaro !! Do you think we should then remove also the the suggestions in the tutorial READMEs, like

gz-sim-yarp-plugins/tutorial/camera/model/README.md

Lines 38 to 46 in 0691f50

	If you are using Linux on WSLg and you have the following error
	~~~
	OGRE EXCEPTION(9:UnimplementedException): in GL3PlusTextureGpu::copyTo at ./RenderSystems/GL3Plus/src/OgreGL3PlusTextureGpu.cpp (line 685)
	~~~
	try forcing software rendering:
	~~~
	export LIBGL_ALWAYS_SOFTWARE=1
	~~~

?

[traversaro]

Yes, I think it make sense to remove also the one in the README, thanks for catching that!

[xela-95]

Rebased and squashed the fixups.

[xela-95]

Super @traversaro !! Approving

[xela-95]

Merging 🚀