Add self-supervised pre-training bundle

[holgerroth]

Is your feature request related to a problem? Please describe. There is growing interest in self-supervised pertaining. MONAI already supports this task in the tutorials https://github.com/Project-MONAI/tutorials/tree/main/self_supervised_pretraining It would be great if this example could be turned into a ready-to-use bundle. Packing of this task into a bundle would also allow the usage in other scenarios, such as federated learning.

Describe the solution you'd like Prepare a bundle for self-supervised pre-training in the model zoo.

Describe alternatives you've considered n/a

Additional context Requested by MONAI FL WG