[Permissions] Schema checking gives unrelated errors

# Command bugs

#### Command name

`[p]permissions acl setglobal/setserver/updateglobal/updateserver`

#### What cog is this command from?

Permissions

#### What were you expecting to happen?

Either get error about incorrect type of key or have Permissions automatically convert int to str.

#### What actually happened?

I got error "Top-level keys must be either `COG` or `COMMAND`"

#### How can we reproduce this issue?

1. Create such yaml permissions file:
```yaml
COMMAND:
8:
176070082584248320: true
```
2. Upload it using one of the commands: `[p]permissions acl setglobal/setserver/updateglobal/updateserver`
3. See error.

---

The above is reproduction for issue that was already fixed, but the unrelated errors can still happen for yaml file like this:
```yaml
COMMAND:
ping:
default_but_spelt_incorrectly: false
```