Fetch cloud plugin metadata faster (#16645)

When logged in to Orca Cloud, the plugin fetch at startup no longer refreshes the token a second time while start() is already refreshing it. It now waits for that refresh and checks the token again. The subscribed and owned plugin requests also run in parallel, so the fetch takes about half as long.

src/slic3r/plugin/CloudPluginService.cpp

@@ -11,6 +11,7 @@
 #include <boost/log/trivial.hpp>
 #include <boost/nowide/fstream.hpp>
 #include <cstddef>
+#include <future>
 #include <memory>
 #include <ios>
 #include <slic3r/plugin/PluginDescriptor.hpp>
@@ -49,16 +50,22 @@ bool CloudPluginService::fetch_manifests_into_descriptors(std::vector<PluginDesc
     unauthorized.clear();
 
     if (m_orca_agent) {
+        // Refresh the token once, then run both requests in parallel.
+        m_orca_agent->ensure_token_fresh("fetch_plugin_manifests");
+        std::vector<PluginDescriptor> mine_descriptors;
+        auto mine = std::async(std::launch::async, [agent = m_orca_agent, &mine_descriptors] {
+            return agent->fetch_mine_manifests_into_descriptors(mine_descriptors);
+        });
+
         int ret = m_orca_agent->fetch_subscribed_manifests_into_descriptors(descriptors, not_found, unauthorized);
+        const int mine_ret = mine.get();
 
         if (ret != 0) {
             BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << ": Failed to get subscribed plugins.";
             return false;
         }
 
-        std::vector<PluginDescriptor> mine_descriptors;
-
-        ret = m_orca_agent->fetch_mine_manifests_into_descriptors(mine_descriptors);
+        ret = mine_ret;
 
         if (ret != 0) {
             BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << ": Failed to get owned plugins.";