Implement a Fixed Schedule dataset from production traces distribution

As a user, i would like to generate a dataset in this format :

`{"timestamp": 0, "input_length": 100, "output_length": 200, "hash_ids": [1001]}
{"timestamp": 500, "input_length": 200, "output_length": 400, "hash_ids": [1002]}
{"timestamp": 1000, "input_length": 550, "output_length": 500, "hash_ids": [1003, 1005]}`

using the distribution from ai gateway traces.

- [ ] Model the probability distribution of the AI gateway
- [ ] Test with AI perf https://github.com/ai-dynamo/aiperf
- [ ] Extract traces from litellm
- [ ] Extract traces from opengatellm