Implement cached mounting strategy

[St4NNi]

We should start our experiments with the cached mounting strategy in a read-only way:

• A configurable cache path on the node should be used as central entry point to download data using the opendal integration
• During the StageVolume phase the data should be downloaded and prepared into a content-hash derived path
• If data already exists do nothing
• Mount the downloaded content to the pod location using the READONLY flag.
• Create a strategy for content checks and writeback