feat: Allows users to see when a model was downloaded and its hash

[WereCatf]

Currently, the webui appears to provide no way of checking when a model was downloaded or its hash. Being able to see those would be helpful in determining, if there's a newer version of the model available, like e.g. Gemma was updated multiple times in a short period of time, and thus whether to delete the current one and add a new one or not.

Show the model's download date and its hash somewhere in the UI. Even better, if there was a proper menu entry for managing the model files and a simple button to update a model.

An auto-update feature would also be extremely nice, but maybe implement the basics first and consider auto-updater for later?

[lainedfles]

View of additional metadata would be helpful but we may want to postpone any auto-update feature as it may be implemented upstream. See https://github.com/ollama/ollama/pull/2179