Fix double quoting and missing new lines in message sent

* Don't encode text inside code block
* Make sure to replace \n with <br> in the html rendering. It's not
  respecting the common mark spec but this is the same behavior as
  Element

src/actionshandler.cpp

@@ -106,7 +106,20 @@ void ActionsHandler::postMessage(const QString &text,
                                  CustomEmojiModel *cem)
 {
     QString rawText = text;
-    QString cleanedText = text.toHtmlEscaped();
+    auto stringList = text.split(QStringLiteral("```"));
+    QString cleanedText;
+    const auto count = stringList.count();
+    for (int i = 0; i < count; i++) {
+        if (i % 2 == 0) {
+            if (i + 1 != count) {
+                cleanedText += stringList[i].toHtmlEscaped() + QStringLiteral("```");
+            } else {
+                cleanedText += stringList[i].toHtmlEscaped();
+            }
+        } else {
+            cleanedText += stringList[i] + QStringLiteral("```");
+        }
+    }
 
     auto preprocess = [cem](const QString &it) -> QString {
         if (cem == nullptr) {