tests: Add infrastructure for testing plugins (#1538)

This PR adds a test architecture to be able to test plugins

Main infrastructure done by @WerWolv

---------

Co-authored-by: WerWolv <werwolv98@gmail.com>

tests/plugins/source/plugins.cpp

@@ -0,0 +1,16 @@
+#include <hex/api/plugin_manager.hpp>
+
+#include <hex/helpers/utils.hpp>
+
+using namespace hex;
+class PluginLoader {
+public:
+    PluginLoader() {
+        for (const auto &dir : fs::getDefaultPaths(fs::ImHexPath::Plugins)) {
+            PluginManager::addLoadPath(dir);
+        }
+
+        PluginManager::load();
+    }
+};
+static PluginLoader pluginLoader;