Neue Masking-Implementierung. closes #151

docs/backend/auth/masking.md

...src/main/java/de/hsrm/sls/subato/auth/masking/Masker.java

...ava/de/hsrm/sls/subato/auth/masking/MaskerSerializer.java

...srm/sls/subato/auth/masking/MaskerSerializerModifier.java

...n/java/de/hsrm/sls/subato/auth/masking/MaskingModule.java

...main/java/de/hsrm/sls/subato/auth/masking/TaskMasker.java

...ava/de/hsrm/sls/subato/auth/masking/UserDetailMasker.java

...va/de/hsrm/sls/subato/auth/masking/UserSummaryMasker.java

.../java/de/hsrm/sls/subato/shared/config/JacksonConfig.java

.../main/java/de/hsrm/sls/subato/tasks/task/dto/TaskDto.java

.../main/java/de/hsrm/sls/subato/user/dto/UserDetailDto.java

...main/java/de/hsrm/sls/subato/user/dto/UserSummaryDto.java