Fix default failure handling so unauthorized subcommands are not exposed in "Did you mean" suggestions

[RareMan666]

1. Register multiple subcommands under the same root, and give the test player no permission for at least one of them.
2. Join with a normal player account and input the root command incorrectly or incompletely.
3. Before this fix, the failure message could include unauthorized subcommands in Failed to find a suitable command
   for your input... Did you mean:.
4. After this fix, only commands visible to the player are suggested.