feat(Dispatcher): Add debug log for controller methods returning raw data not wrapped in Response

[provokateurin]

Summary

Returning plain data is allowed and some legacy code still does it.
Wrapping with Response or one of it's inheritors is preferred, as it gives better control over the entire response and also allows OpenAPI to work with it (openapi-extractor doesn't allow returning raw data for a good reason).

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[nickvergessen]

Which endpoints do it?

[provokateurin]

Which endpoints do it?

For example

server/apps/files_external/lib/Controller/AjaxController.php

Line 76 in d61d62b

public function saveGlobalCredentials($uid, $user, $password) {

This was just the one that lead me to add this, I've definitely seen it a few times in other places as well (but I don't remember where).