32-bit signed int is not enough for transfer rates

[HanabishiRecca]

libtorrent version (or branch): 2.0.10

platform/architecture: Linux x86-64

compiler and compiler version: gcc 14.1.1

As the title says, I'm actually able to acheive transfers rates more than 2 GiB/s in qBittorrent and exceed the max int32 value.
This leads to weird results. See qbittorrent/qBittorrent#21003 for details.

The root of the problem is fairly straghtforward:

libtorrent/include/libtorrent/torrent_status.hpp

Lines 316 to 317 in ba3a13c

	int download_rate = 0;
	int upload_rate = 0;

libtorrent/include/libtorrent/torrent_status.hpp

Lines 323 to 324 in ba3a13c

	int download_payload_rate = 0;
	int upload_payload_rate = 0;

Maybe it's time to promote the values to int64_t.

[glassez]

IMO, many of the data sizes used are already obsolete, so now problems related to speeds and sizes are becoming more common (e.g. #7735). Interestingly, in some such cases, it is clear that the algorithms used normally cope with the current needs of users, it is enough only to increase the data types used.