feat: add the EnvironmentDetector utility class and environmentdetector service

[paulbalandan]

Description
This PR adds the EnvironmentDetector utility class as a simple mockable wrapper to accessing the ENVIRONMENT constant, allowing us to test previously unreachable code branches dependent on the current environment.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[michalsn]

I think it's a good change.

I added some suggestions to the phpdocs / user guide.

[neznaika0]

Maybe skip double trim()?

Suggested change

	public function __construct(?string $environment = null)
	{
	if ($environment !== null && trim($environment) === '') {
	throw new InvalidArgumentException('Environment cannot be an empty string.');
	}
	$this->environment = $environment !== null ? trim($environment) : ENVIRONMENT;
	}
	public function __construct(?string $environment = null)
	{
	$environment = $environment !== null ? trim($environment) : ENVIRONMENT;
	if ($environment === '') {
	throw new InvalidArgumentException('Environment cannot be an empty string.');
	}
	$this->environment = $environment;
	}

[neznaika0]

It seems that php:class is used to describe classes and provide links to their descriptions. In this case, it looks like an ordinary code mention and you can skip it.

In general, what was the primary point of describing classes and functions in documentation in a special style? It looks clumsy. If you follow the style, you need to manually perform the functions of phpDocumentor. Due to the possible migration from Sphinx, this has added to the problems.

[neznaika0]

Add to system/Config/BaseService.php:

 * @method static EnvironmentDetector environmentdetector(?string $environment = null, bool $getShared = true)

[neznaika0]

I would also shorten (19 > 11 chars) the name to envdetector, env_detector, although a clear description is more important.

[paulbalandan]

how about just environment? it would read more naturally as service('environment')->isProduction() etc.

the class name EnvironmentDetector was chosen because it may clash with the env command's class when importing in IDE.

[neznaika0]

Then it might be worth adding everything related to ENV to the service. And it will replace or complement the built-in DotEnv... At the moment, the "detector" clearly indicates its role.

[paulbalandan]

Ok. I'll just rename to envdetector.