Allocate uninit bench

• Figure out if it is worth it
• Figure if there's a good way to read the payloads into allocated but uninitialized memory.

Best way

#[inline(always)]
fn load_payload_raw(&mut self, payload_size: usize) -> Result<Vec<u8>, std::io::Error> {
    let mut payload = Vec::with_capacity(payload_size);

    // The read into raw memory through the raw pointer is safe because we just allocated the capacity
    unsafe {
        let ptr = payload.as_mut_ptr();
        let slice = std::slice::from_raw_parts_mut(ptr, payload_size);

        Read::read_exact(&mut self.reader, slice)?;

        // Safe because we just read into all this memory that we now have initialized to valid data
        payload.set_len(payload_size)
    }

    Ok(payload)
}