[WIP] Fix ban by software version, some other under-hood changes

- Use updated version of upstream go-xmpp + fixes on client-side
- Introduce golangci-lint v2 + fixes
- Move especially noisy debugging stuff to separate config handles to be able to switch them off
- Add a bit debug to ban by software path

vendor/github.com/xmppo/go-xmpp/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
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+
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+in the documentation and/or other materials provided with the
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+
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