More error handling to help diagnose issues in CI

src/dds/cli/cmd/repoman_add.cpp

         [](dds::e_system_error_exc e, dds::e_open_repo_db db) {
             dds_log(error, "Error while opening repository database {}: {}", db.path, e.message);
             return 1;
-        },
-        [](dds::e_system_error_exc e, neo::url url, http_response_info) {
-            dds_log(error,
-                    "An error occured while downloading [.bold.red[{}]]: {}"_styled,
-                    url.to_string(),
-                    e.message);
-            return 1;
         });
 }
 

src/dds/cli/error_handler.cpp

 #include "./options.hpp"
 
 #include <dds/error/errors.hpp>
+#include <dds/util/http/pool.hpp>
 #include <dds/util/log.hpp>
 #include <dds/util/result.hpp>
 #include <dds/util/signal.hpp>
 #include <boost/leaf/handle_error.hpp>
 #include <boost/leaf/handle_exception.hpp>
 #include <boost/leaf/result.hpp>
+#include <fansi/styled.hpp>
 #include <fmt/ostream.h>
 #include <json5/parse_data.hpp>
 #include <neo/scope.hpp>
 #include <fstream>
 
 using namespace dds;
+using namespace fansi::literals;
 
 namespace {
 
         dds_log(critical, "Operation cancelled by the user");
         return 2;
     },
+    [](dds::e_system_error_exc e, neo::url url, http_response_info) {
+        dds_log(error,
+                "An error occured while downloading [.bold.red[{}]]: {}"_styled,
+                url.to_string(),
+                e.message);
+        return 1;
+    },
+    [](dds::e_system_error_exc e, network_origin origin, neo::url* url) {
+        dds_log(error,
+                "Network error communicating with .bold.red[{}://{}:{}]: {}"_styled,
+                origin.protocol,
+                origin.hostname,
+                origin.port,
+                e.message);
+        if (url) {
+            dds_log(error, "  (While accessing URL [.bold.red[{}]])"_styled, url->to_string());
+        }
+        return 1;
+    },
     [](e_system_error_exc exc, boost::leaf::verbose_diagnostic_info const& diag) {
         dds_log(critical,
                 "An unhandled std::system_error arose. THIS IS A DDS BUG! Info: {}",

src/dds/util/http/pool.cpp

 
         if (resp.is_error()) {
             client.discard_body(resp);
-            throw boost::leaf::exception(http_status_error("Received an error from HTTP"));
+            throw BOOST_LEAF_EXCEPTION(http_status_error("Received an error from HTTP"));
         }
 
         if (resp.is_redirect()) {
             client.discard_body(resp);
             if (i == 100) {
-                throw boost::leaf::exception(
+                throw BOOST_LEAF_EXCEPTION(
                     http_server_error("Encountered over 100 HTTP redirects. Request aborted."));
             }
             auto loc = resp.headers.find("Location");
             if (!loc) {
-                throw boost::leaf::exception(
+                throw BOOST_LEAF_EXCEPTION(
                     http_server_error("Server sent an invalid response of a 30x redirect without a "
                                       "'Location' header"));
             }