Fix a sign propagation in calculating transaction size statistics

This patch fixes bugs in sign propagation disovered with
-Wsign-conversion compilar flag and related integer overflows in
dnf5::print_transaction_size_stats(), like this one:

    dnf5/main.cpp: In function ‘void dnf5::print_transaction_size_stats(Context&)’:
    dnf5/main.cpp:785:29: error: conversion to ‘long long unsigned int’ from ‘int64_t’ {aka ‘long int’} may change the sign of the result [-Werror=sign-conversion]
      785 |             in_pkgs_size += pkg_size;
          |                             ^~~~~~~~

There were more ways of fixing, but I choose this one:

Use unsigned integers because an integer overflow for signed types is
undefined in C++. I choose unsigned long long int to follow what
get_download_size() and get_install_size() returns. Otherwise, we would
have to add another check whether the value fits into e.g. uint64_t.
Unless we chose uintmax_t.

Explicitly type-cast counters, with a prior range check, on passing
them to libdnf5::cli::utils::units::to_size(). Otherwise, we would
have to add to_size() for unsigned integers to the public API.
(Actuallly to_size() should have been for unsigned integeres from the
very beginning. Package sizes cannot be negative.)

Not printing the transaction size statistics if an irrepresentible
value occurs. Adding more branches to the already complicated code for
the very improbably corner cases does not make much sense.

(I tried also a different implemeation with keeping int64_t as the
counters, but the code was longer and uglier.)

Related: #1701

dnf5/main.cpp

@@ -85,6 +85,7 @@ along with libdnf.  If not, see <https://www.gnu.org/licenses/>.
 #include <cstring>
 #include <filesystem>
 #include <iostream>
+#include <utility>
 
 constexpr const char * DNF5_LOGGER_FILENAME = "dnf5.log";
 
@@ -773,29 +774,38 @@ static void print_versions(Context & context) {
 }
 
 static void print_transaction_size_stats(Context & context) {
-    int64_t in_pkgs_size{0};
-    int64_t download_pkgs_size{0};
-    int64_t install_size{0};
-    int64_t remove_size{0};
+    unsigned long long int in_pkgs_size{0};
+    unsigned long long int download_pkgs_size{0};
+    unsigned long long int install_size{0};
+    unsigned long long int remove_size{0};
 
     for (const auto & trans_pkg : context.get_transaction()->get_transaction_packages()) {
         const auto pkg = trans_pkg.get_package();
         if (transaction_item_action_is_inbound(trans_pkg.get_action())) {
             const auto pkg_size = pkg.get_download_size();
             in_pkgs_size += pkg_size;
+            if (in_pkgs_size < pkg_size)
+                return;
             if (!pkg.is_available_locally()) {
                 download_pkgs_size += pkg_size;
+                if (download_pkgs_size < pkg_size)
+                    return;
             }
             install_size += pkg.get_install_size();
+            if (install_size < pkg.get_install_size())
+                return;
         } else if (transaction_item_action_is_outbound(trans_pkg.get_action())) {
             remove_size += pkg.get_install_size();
+            if (remove_size < pkg.get_install_size())
+                return;
         }
     }
 
-    if (in_pkgs_size != 0) {
-        const auto [in_pkgs_size_value, in_pkgs_size_unit] = libdnf5::cli::utils::units::to_size(in_pkgs_size);
+    if (in_pkgs_size != 0 && std::in_range<int64_t>(in_pkgs_size) && std::in_range<int64_t>(download_pkgs_size)) {
+        const auto [in_pkgs_size_value, in_pkgs_size_unit] =
+            libdnf5::cli::utils::units::to_size(static_cast<int64_t>(in_pkgs_size));
         const auto [dwnl_pkgs_size_value, dwnl_pkgs_size_unit] =
-            libdnf5::cli::utils::units::to_size(download_pkgs_size);
+            libdnf5::cli::utils::units::to_size(static_cast<int64_t>(download_pkgs_size));
         context.print_info(libdnf5::utils::sformat(
             _("Total size of inbound packages is {:.0f} {:s}. Need to download {:.0f} {:s}."),
             in_pkgs_size_value,
@@ -804,9 +814,14 @@ static void print_transaction_size_stats(Context & context) {
             dwnl_pkgs_size_unit));
     }
 
-    const auto [install_size_value, install_size_unit] = libdnf5::cli::utils::units::to_size(install_size);
-    const auto [remove_size_value, remove_size_unit] = libdnf5::cli::utils::units::to_size(remove_size);
-    const auto size_diff = install_size - remove_size;
+    if (!std::in_range<int64_t>(install_size) || !std::in_range<int64_t>(remove_size) ||
+        !std::in_range<int64_t>(install_size - remove_size))
+        return;
+    const auto [install_size_value, install_size_unit] =
+        libdnf5::cli::utils::units::to_size(static_cast<int64_t>(install_size));
+    const auto [remove_size_value, remove_size_unit] =
+        libdnf5::cli::utils::units::to_size(static_cast<int64_t>(remove_size));
+    const int64_t size_diff = static_cast<int64_t>(install_size - remove_size);
     const auto [size_diff_value, size_diff_unit] = libdnf5::cli::utils::units::to_size(std::abs(size_diff));
     if (size_diff >= 0) {
         context.print_info(libdnf5::utils::sformat(