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

- Use updated version of upstream go-xmpp + fixes on client-side
- Still waiting for https://github.com/xmppo/go-xmpp/pull/215
- Introduce golangci-lint v2 + fixes

internal/jabber/commands.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 
 	"github.com/davecgh/go-spew/spew"
-	"github.com/eleksir/go-xmpp"
+	"github.com/xmppo/go-xmpp"
 )
 
 // Cmd парсит команды из чятика.