Order of events is not correct

[asgrim]

        $agent->webTransaction('Yay', static function () use ($agent) : void {
            $agent->instrument('test', 'foo', static function () use ($agent) : void {
                sleep(1);
                $agent->instrument('test', 'foo2', static function () : void {
                    sleep(1);
                });
            });
            $agent->tagRequest('testtag', '1.23');
        });

At the moment, we're getting events in the order more like:

• StartRequest
• StartSpan test/foo2
• TagSpan test/foo2 stack
• StopSpan test/foo2
• StartSpan test/foo
• TagSpan test/foo stack
• StopSpan test/foo
• TagRequest testtag 1.23
• StartSpan Controller/Yay
• TagSpan Controller/Yay stack
• StopSpan Controller/Yay
• FinishRequest

The order events is wrong because the StartSpan test/foo2 refers to the parent_id of the StartSpan Controller/Yay which doesn't "exist" yet. Also, the order doesn't really make sense due to the order in which the spans are started/stopped etc.

These events should be reordered to their "natural" order, for example:

• StartRequest
• StartSpan Controller/Yay
• StartSpan test/foo
• StartSpan test/foo2
• TagSpan test/foo2 stack
• StopSpan test/foo2
• TagSpan test/foo stack
• StopSpan test/foo
• TagRequest testtag 1.23
• TagSpan Controller/Yay stack
• StopSpan Controller/Yay
• FinishRequest