Add helper function for chunked reads

[sosthene-nitrokey]

A read_to_end function in streaming::utils.

I don't want to do a method that takes or return a Bytes<N> because the whole point of the streaming API is for file that are too large and for which we don't want to have large stack allocations.

What I think we may want to have a function that reads a file and insert it to a &mut Vec, but I was not sure which type should be used?

In opcard and PIV we have a Reply wrapper type around Bytes which are themselves a wrapper around heapless::Vec<u8,N>.

Maybe we could have something like read_to_end(path, location, buffer: &mut impl Write) but I'm not sure which Write trait we should use (std::io::Write is not available in core). Maybe we should come up with our own?

[sosthene-nitrokey]

Also there are many cases where we want to have the length of the file before we begin writing stuff to the output. This is for example the case when dealing with TLV data.