Add support for silhouette score

src/experiments/groovy/TemperatureClustering.groovy

src/main/java/fr/irit/smac/amas4dc/AMAS4DC.java

src/main/java/fr/irit/smac/amas4dc/amas/AMASOption.java

src/main/java/fr/irit/smac/amas4dc/amas/ClusterAgent.java

...mas4dc/amas/controller/AMAS4DCCommandAndQueryHandler.java

...c/amas4dc/amas/controller/MissingDataPointsException.java

...it/smac/amas4dc/amas/controller/query/ExtendedResult.java

...controller/query/RetrieveClustersExtendedResultQuery.java

src/main/java/fr/irit/smac/amas4dc/cluster/Cluster.java

...in/java/fr/irit/smac/amas4dc/cluster/ExtendedCluster.java

...r/irit/smac/amas4dc/cluster/ExtendedClusterException.java

.../irit/smac/amas4dc/cluster/SilhouetteScoreCalculator.java