This PR adds capabilities for flow sensitive analysis:

• Scramble now builds CFG for methods/functions
• Implemented a simple API for querying the CFG to find value origins and expression types at a flow node.

To retrieve the instance of CGF (specifically flow container), you can call getFlowContainer on method definition:

$classDefinition = app(Infer::class)->analyzeClass(UserResource::class);

$flow = $classDefinition->getMethod('response')->getFlowContainer();

On flow container instance currently there are 2 methods considered as public API.

• findValueOriginsByExitType (callable(Type): bool): Flow\Node[] - allows to find the nodes where some specific exit values created by the type.

For example, this function returns 42|1:

function foo () {
    $a = 1;
    if (mt_rand(0, 1) === 42) {
        $a = 42;
    }
    return $a;
}

You can find $a = 42 flow node by using findValueOriginsByExitType:

use Dedoc\Scramble\Support\Type\Literal\LiteralIntegerType;

$nodes = $flowContainer->findValueOriginsByExitType(
    fn (Type $t) => $t instanceof LiteralIntegerType && $t->value === 42,
);

• getTypeAt (Expr, Flow\Node) - allows to get the type of the expression at a given flow node. This will also take conditional type narrows in consideration, currently Identical checks are supported:

function foo () {
    $b = mt_rand(0, 100);
    if ($b === 42) {
        // when checking `$b` type here, Scramble will know it is `42`.
    }
    return 0;
}