WIP: delete users

caosdb-proto

src/main/java/org/caosdb/server/accessControl/Role.java

...atabase/backend/implementation/MySQL/MySQLDeleteRole.java

...abase/backend/implementation/MySQL/MySQLRetrieveRole.java

...main/java/org/caosdb/server/database/proto/ProtoUser.java

src/main/java/org/caosdb/server/entity/Message.java

...aosdb/server/grpc/AccessControlManagementServiceImpl.java

.../org/caosdb/server/transaction/DeleteRoleTransaction.java

src/main/java/org/caosdb/server/utils/ServerMessages.java