Probability Based Sampling Tracing

Reproduction for this issue.

Installation

1. Clone this repo.
2. Install dependencies: npm install.
3. Run migrations: npx prisma migrate dev.
4. Start jaeger: docker-compose up -d
5. Start the server: npm run dev.
6. Test out the example endpoint a few times: http://localhost:4000/users/random.
7. See the generated traces in Jaeger: http://localhost:16686/