feat(share/getter): Cascade Getter Discards Successful Samples on Partial Failure

[walldiss]

Implementation ideas

When using the cascade getter, if any of the requested samples fail to retrieve, the system retries the entire sampleCoordinates set with the next fallback getter. This process discards any samples that were successfully retrieved in the previous attempt. While this currently works because the bitswap getter is the last in the sequence, it may lead to issues if the order changes or additional getters are introduced. This behavior lacks proper support in the current implementation and could become problematic and difficult to debug in the future.

Suggested Improvement:
Implement proper handling for partial successes to ensure that retrieved samples are not discarded unnecessarily. Modify the cascade getter to retain successfully retrieved samples when retrying with fallback getters.

Becomes relevant after #3891 is merged