Add Hash of HubId to fetchUpdate request

### Please agree to the following

- [X] I have searched [existing issues](https://github.com/cryptomator/hub/issues?q=) for duplicates
- [X] I agree to follow this project's [Code of Conduct](https://github.com/cryptomator/hub/blob/develop/.github/CODE_OF_CONDUCT.md)

### Summary

Add with a custom header the hash of hubId to the fetchUpdate() request in frontend

### Motivation

In https://github.com/cryptomator/hub/pull/121#discussion_r945681432 it was suggested to add the hash of the hubId to the fetchUpdate() request to apply statistics later on on the update server.

Currently, this is not possible, because the fetching the HubId requires admin privileges, while the update request works for every user.

It was suggested to extend the VersionDto to contain the hash of the hubId.

### Considered Alternatives

_No response_

### Anything else?

See https://github.com/cryptomator/hub/pull/121#discussion_r945681432