Add CI workflow to check line endings of all source files (#2082)

In addition, all found errors (formatting & line ending) have been fixed in this PR.

src/util/Overloaded.hpp

@@ -1,13 +1,13 @@
-#pragma once
-
-namespace chatterino {
-
-template <class... Ts>
-struct Overloaded : Ts... {
-    using Ts::operator()...;
-};
-
-template <class... Ts>
-Overloaded(Ts...)->Overloaded<Ts...>;
-
-}  // namespace chatterino
+#pragma once
+
+namespace chatterino {
+
+template <class... Ts>
+struct Overloaded : Ts... {
+    using Ts::operator()...;
+};
+
+template <class... Ts>
+Overloaded(Ts...) -> Overloaded<Ts...>;
+
+}  // namespace chatterino