add blockchain/linked list history to higher-level products

[j-haacker]

Is your feature request related to a problem? Please describe.
Currently, the file names are the only means to identify the contents of a file. Often, even inspection of the data cannot unambiguously trace their origin. However, for scientific purposes the user might need to verify the data integrity. Especially in automated setups, filenames are not sufficiently robust to ensure that the contents are what the user expects them to be.

Describe the solution you'd like
I could imagine a git branch/blockchain/linked list/... -like structure. It should be apparent what version of the input data and what version of cryoswath was used at different stages. At least, a l4-file should identify its parent l3-file.