[Fix] CMake using testflag enabled

Problem:

• With the current verison, the cmake configuration fails when configured with BUILD_UNITTEST or BUILD_BLACKBOXTESTS if the directory test and the according CMakeLists.txt file does not exist.

Additionally:

• ecological_assessment used deprecated libraries (aircraftGeometry & svgPlot). Those are not accessible anymore which leads to a failing configuration with one or both of the used flags

Solution: Added a specific check whether there is a test directory which contains a CMakeLists.txt. If so, the subdirectory will be added, otherwise it skips the test configuration

For ecological_assessment, the library linkage is updated.

Unix test → Successful
Windows test → to test by reviewer