Manipulations overwrite when called multiple times (support for stackable calls)

[jorenvh]

@freekmurze Currently, a manipulation can only be used once because the method name is used as the array key.
I have a use case where I'm adding text to an image using a backdrop approach (similar to subtitles in early video formats) to ensure readability on both light and dark backgrounds.

Would you be open to a PR that tracks calls to each manipulation and generates indexed keys like text__0, text__1, etc.? The suffix would then be stripped before calling the actual manipulation method.

An alternative approach would be to allow the Manipulations class to be specified via a config file, enabling control of this behavior at the application level. Currently, we're unable to decorate it since it's not resolved through dependency injection.

Manipulations.php

public function __call(string $method, array $parameters): self
{
        $this->addManipulation($method, $parameters);

        return $this;
}

public function addManipulation(string $name, array $parameters = []): self
{
        $this->manipulations[$name] = $parameters;

        return $this;
}

public function apply(ImageDriver $image): void
{
        foreach ($this->manipulations as $manipulationName => $parameters) {
            $parameters = $this->transformParameters($manipulationName, $parameters);
            $image->$manipulationName(...$parameters);
        }
}

An alternative approach could be to have the Manipulation class coming from a config file in order to control the behaviour on application level. Currently we are not able to decorate it as it's not injected via dependency injection.