Add basic lua scripting capabilities (#4341)

The scripting capabilities is locked behind a cmake flag, and is not enabled by default.

Co-authored-by: nerix <nerixdev@outlook.de>
Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/singletons/Paths.cpp

@@ -141,6 +141,7 @@ void Paths::initSubDirectories()
     this->messageLogDirectory = makePath("Logs");
     this->miscDirectory = makePath("Misc");
     this->twitchProfileAvatars = makePath("ProfileAvatars");
+    this->pluginsDirectory = makePath("Plugins");
     this->crashdumpDirectory = makePath("Crashes");
     //QDir().mkdir(this->twitchProfileAvatars + "/twitch");
 }