Communication between users and subscription. Subscription added to Docker Compose.

Created by: oblivisheee

This pull request includes several changes to improve the subscription service, including updates to configuration files, Docker setup, and error handling. The most important changes are grouped by theme below:

Configuration and Setup:

• Removed the users-docker-config.json file and updated docker-compose.yaml to remove the volume mount for this file. Added a new subscription service with its configuration. [1] [2]
• Added a new network nginx to docker-compose.yaml for better network isolation. [1] [2]
• Updated the nginx.conf to include new locations for subscription-related routes.

Dependency Management:

• Added new dependencies bytes and redis to subscription/Cargo.toml for handling Redis operations.

Error Handling:

• Enhanced the Error enum in subscription/src/errors.rs to include new variants for Redis and NATS errors. Added corresponding methods to handle these errors. [1] [2] [3] [4]

Redis Integration:

• Updated various functions in subscription/sql/funcs_plans.surql and subscription/sql/funcs_subs.surql to include type annotations for parameters. [1] [2] [3] [4]
• Integrated Redis caching in subscription/src/interfaces.rs to cache subscription plans and invalidate the cache on updates. [1] [2] [3]

Dockerfile and Build:

• Added a new Dockerfile and justfile for the subscription service, including a basic setup for building and running the service. [1] [2]