Added clip creation support 🎬 (#2271)

You can create clips with `/clip` command, `Alt+X` keybind or `Create a clip` option in split header's context menu. This requires a new authentication scope so re-authentication will be required to use it.

Co-authored-by: Leon Richardt <leon.richardt@gmail.com>
Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/providers/twitch/api/Helix.hpp

@@ -135,6 +135,23 @@ struct HelixGame {
     }
 };
 
+struct HelixClip {
+    QString id;  // clip slug
+    QString editUrl;
+
+    explicit HelixClip(QJsonObject jsonObject)
+        : id(jsonObject.value("id").toString())
+        , editUrl(jsonObject.value("edit_url").toString())
+    {
+    }
+};
+
+enum class HelixClipError {
+    Unknown,
+    ClipsDisabled,
+    UserNotAuthenticated,
+};
+
 class Helix final : boost::noncopyable
 {
 public:
@@ -185,14 +202,22 @@ public:
     void getGameById(QString gameId, ResultCallback<HelixGame> successCallback,
                      HelixFailureCallback failureCallback);
 
+    // https://dev.twitch.tv/docs/api/reference#create-user-follows
     void followUser(QString userId, QString targetId,
                     std::function<void()> successCallback,
                     HelixFailureCallback failureCallback);
 
+    // https://dev.twitch.tv/docs/api/reference#delete-user-follows
     void unfollowUser(QString userId, QString targetlId,
                       std::function<void()> successCallback,
                       HelixFailureCallback failureCallback);
 
+    // https://dev.twitch.tv/docs/api/reference#create-clip
+    void createClip(QString channelId,
+                    ResultCallback<HelixClip> successCallback,
+                    std::function<void(HelixClipError)> failureCallback,
+                    std::function<void()> finallyCallback);
+
     void update(QString clientId, QString oauthToken);
 
     static void initialize();