Magento sniff codes do not match expected format (too many `.`)

Nobody has claimed this yet.

### Preconditions
1. Use any version of the magento coding standard

### Steps to reproduce
1. Try to use the `--exclude` flag on the CLI to exclude a magento sniff

```bash
$ ./vendor/bin/phpcs -s --standard=Magento2 --exclude=Magento2.Annotation.MethodArguments.MethodArguments src
ERROR: The specified sniff code "Magento2.Annotation.MethodAnnotationStructure.MethodArguments" is invalid

Run "phpcs --help" for usage information
```

### Expected result
1. I can run `phpcs` with the specified rule excluded

### Actual result
I get an error from phpcs as it doesnt expect this many `.` in the sniff codes

https://github.com/squizlabs/PHP_CodeSniffer/blob/b314140057170a81075556a71764f2f302e3b8be/src/Config.php#L851-L859

`squizlabs/php_codesniffer` only expects 2 `.` within a rule name

`--exclude=Magento2.Annotation.MethodArguments.MethodArguments` has 3

When I hack out the check in `vendor/squizlabs/php_codesniffer/src/Config.php` it seems to exclude the rule okay so not sure why they're being strict there. But it still seems like the way the Magento rules are defined they're not fully compatible with `squizlabs/php_codesniffer`

### Workaround

Define my own ruleset which excludes the rules i'm suppressing.

Start with the linked src/Config.php check around lines 851-859 and reproduce the reported ./vendor/bin/phpcs command using the Magento2 standard and --exclude option. Trace how the sniff code is validated against Magento's rule names. Done means the documented Magento sniff can be excluded through the CLI without the invalid-code error.

Written by the indexing model from the issue text.