Make OpenTelemetry work with FiberBoundContextStorage

It may work if core patched to pass context into fiber but ++ to find out general approach without hacking every place where Fiber is created

AUto-instrumentation using FFI+ZTS also overkill

Module could provide hybrid context and raise required OT version to 1.1

Kinda

use OpenTelemetry\Context\ContextStorage;
use OpenTelemetry\Context\FiberBoundContextStorage;

class HybridContextStorage extends ContextStorage {
    private $fiberStorage;
    private $defaultStorage;

    public function __construct() {
        $this->fiberStorage = new FiberBoundContextStorage();
        $this->defaultStorage = new ContextStorage();
    }

    public function current(): Context {
        if (\Fiber::getCurrent()) {
            return $this->fiberStorage->current();
        }
        return $this->defaultStorage->current();
    }

    public function attach(Context $context): Scope {
        if (\Fiber::getCurrent()) {
            return $this->fiberStorage->attach($context);
        }
        return $this->defaultStorage->attach($context);
    }
}

Measuring queries executed in big-pipe and while rendering also can give wrong results on timing for db-queries

Probably makes sense to patch core so it will react on fiber suspend,
also maybe to add attribute to spans to point out that span generated inside of fiber and time could be inaccurate