Add a fallback mechanism to look for KeptnEvaluationDefinitions

Add a fallback mechanism to look for KeptnEvaluationDefinitions: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). KLT fallbacks to search for a KeptnEvaluationDefinition in the namespace in which it's deployed if it cannot find it in the namespace of the KeptnApp