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/providers/irc/IrcCommands.hpp

@@ -1,12 +1,12 @@
-#pragma once
-
-#include "common/Outcome.hpp"
-
-namespace chatterino {
-
-class IrcChannel;
-
-Outcome invokeIrcCommand(const QString &command, const QString &params,
-                         IrcChannel &channel);
-
-}  // namespace chatterino
+#pragma once
+
+#include "common/Outcome.hpp"
+
+namespace chatterino {
+
+class IrcChannel;
+
+Outcome invokeIrcCommand(const QString &command, const QString &params,
+                         IrcChannel &channel);
+
+}  // namespace chatterino