This is a really good question! This whole system you are talking about is popular in Europe, and I believe they have the grading system setup in the school systems. If you find a source that allows you to test this online let me know, but I’m pretty sure there isn’t anything like that available.
My suggestion if you want to understand your ability level–post a video in the forums and I’ll give you some insight. Only labeling yourself as a beginner or intermediate player can be rather broad, so I might be able to add some insight to it. For example, I might say your rhythm is really good but your intonation needs practice. Those are things I would find more valuable regarding ability level. Many people are very good in some areas (intermediate level I would say), but need to catch up in other areas.
Hope you decide to post a video in the forums! Let me know if you have any other questions.