[WIP] New RandomNumberGenerator API

[pjfanning]

• relates to Possibly replace ThreadLocalRandom #1749
• experimental new RandomNumberGenerator API that allows us to plug in different RandomGenerators based on the config (to be done)
• so far, I'm just plugging in the API to catch compile issues
• later, I will add the new configs and RandomNumberGenerator.get() will react to the config
• for performance reasons, the init of RandomNumberGenerator.get() will happen once so the config will be read just once
• not necessarily going to be merged

[He-Pin]

Another thing is with the current implementation, the virtual thread is never pooled, which means the ThreadLocalRandom will not leak the thread locals

[pjfanning]

So far, it seems that the performance is lower if you do not use the ThreadLocalRandom. The speed is still good and I don't think we are in a hotspot area where the small perf loss here will make a big diff. I don't think anyone should use this option unless they have a good reason to worry about their virtual thread usage leading to an excessive amount of object instance creation (one ThreadLocalRandom instance per virtual thread).