This required multiple changes:
- Make hashes non-copiable because they contain a heap allocated pointer
- Reference classes via `NonnullOwnPtr` only (they are non-copiable)
- Drop all existing hashes implementations
- Use the `OpenSSLHashFunction` base class to implement the same hashes
I was not able to come up with a way to divide this commit into multiple
without increasing the amount of changes.
Nothing breaks with this commit!
