Performance/LowExpiryCacheTime: various sniff improvements

[jrfnl]

Performance/LowExpiryCacheTime: move a parse error test to own test case file

Performance/LowExpiryCacheTime: improve the tests

• Add some more variations to the pre-existing tests:
  • Non-lowercase function call(s).
  • Fully qualified function calls.
  • Use PHP 7.3+ trailing comma's in a few function calls.
• Add tests for some edge-cases (empty text string, parse error).
• Add tests with a few additional PHP syntaxes to document these are handled correctly.

Performance/LowExpiryCacheTime: add support for PHP 7.4+ numeric literals and 8.1+ octal literals

While PHPCS fully supports these syntaxes at the tokenizer level, this sniff includes the contents of the found token in a string which will be run through eval(), which means that if the number was originally provided in a PHP 7.4+ syntax and the sniffs are run on PHP 7.2, the eval will result in a fatal error, breaking the sniff (and possibly the PHPCS run).

By using the PHPCSUtils Numbers class, we can bypass this and retrieve the decimal value of a integer/float, no matter in what syntax the number is provided. If we then use the decimal value in the string which will be run through eval(), the potential fatal error is avoided.

Includes tests.

Performance/LowExpiryCacheTime: cleaner error message

The PHPCSUtils PassedParameters::getParameters() return value includes a 'clean' array index, which contains the contents of the parameter stripped of surrounding whitespace and comments.

The LowExpiryCacheTime sniff uses the parameter contents in the error message, so using the clean value makes for a more readable error message.

Includes updating two pre-existing tests.

Before:

 76 | WARNING | Cache expiry time could not be determined. Please inspect that the fourth parameter passed to wp_cache_set() evaluates to 300
     |         | seconds or more. Found: "20 * $time /*comment*/" (WordPressVIPMinimum.Performance.LowExpiryCacheTime.CacheTimeUndetermined)

After:

  76 | WARNING | Cache expiry time could not be determined. Please inspect that the fourth parameter passed to wp_cache_set() evaluates to 300
     |         | seconds or more. Found: "20 * $time" (WordPressVIPMinimum.Performance.LowExpiryCacheTime.CacheTimeUndetermined)

Performance/LowExpiryCacheTime: add support for handling PHP 8.0+ function calls using named parameters

Includes tests.

Closes #532