Moved projects to reflect project dependencies.

.gitlab-ci.yml

src/core/.mvn/maven.config

.../statistics/writer/AbstractCandidateStatisticsWriter.java

...core/main/statistics/fitness/BestCandidateStatistics.java

...re/main/statistics/internal/MultipleStatisticsWriter.java

src/core/pom.xml

src/plugins/.mvn/maven.config

src/plugins/de.evoal.approximative.density/pom.xml

...approximative/density/ea/fitness/DensityBasedFitness.java

...ative/density/ea/fitness/GaussianBasedDensityFitness.java

...imative/density/ea/fitness/KernelBasedDensityFitness.java

...l/approximative/density/ea/fitness/QuadrupelFunction.java

...e/density/ea/surrogate/gof/AbstractDensityEstimation.java

...e/density/ea/surrogate/gof/GaussianDensityEstimation.java

...ive/density/ea/surrogate/gof/KernelDensityEstimation.java

...voal/approximative/density/model/CustomKernelDensity.java

...ava/de/evoal/approximative/density/model/DensityData.java

...voal/approximative/density/model/GaussianDensityData.java

.../evoal/approximative/density/model/KernelDensityData.java

...voal.approximative.density/src/main/java/module-info.java