Fix handling of booleans in conditions

[ruudk]

Booleans are currently handled very poorly.

Especially when the context contains real true or false booleans.

The Amplitude UI often shows True and False as auto completions.

Since this SDK uses strval to convert a boolean to a string value, a boolean true becomes string 1. And boolean false becomes string 0.

But if the flag's condition uses string True or False, it won't match.

To solve this, we add more test cases, and refactor the matchesIs in the EvaluationEngine.

I also tried to add the following test cases:

        yield [false, ['false']];
        yield [false, ['False']];
        yield [false, ['0']];

But these fail because they are intercepted and handled as nullables:

experiment-php-server/src/EvaluationCore/EvaluationEngine.php

Lines 84 to 89 in 3527848

	private function matchCondition(array $target, array $condition): bool
	{
	$propValue = select($target, $condition['selector']);
	if (!$propValue && $propValue !== '0') {
	return $this->matchNull($condition['op'], $condition['values']);

While inspecting the code responsible for that, I really think this Evaluation Engine shouldn't have been made loosely typed but strictly typed instead 🤯

[promptless]

📝 Documentation updates detected!

New suggestion: Update PHP SDK documentation for boolean handling in conditions

[tyiuhc]

@ruudk thanks for raising this issue! This bug is addressed in v1.2.3, please let us know if it is not functioning as expected.