create a new field into the gguf format to distinguish different releases of the same model

[littlett77]

Given that some times a model gets updated (on repos such like HuggingFace) because of the fixing of minor issues but the different releases of the same model cannot be distinguished by otherwise identical name, I would like to suggest that a future GGUF format should be able to address this issue by incorporating among the various model params things like the specific release creation date/time or something like the output of llama-gguf-hash --uuid or a partial hash relative to the model core