Essential API setup

[sjmiller609]

Boilerplate for golang API:

• OpenAPI code gen
• Dependency injection
• Configuration
• Error handling
• Testing
• Authentication
• Handlers / services directory layout

[mesa-dot-dev]

Mesa Description

This PR lays the foundational groundwork for the new API server. It sets up the basic server structure, including the main application entrypoint, configuration, and a health check endpoint. This initial setup is crucial for enabling future development of specific API functionalities.

Key changes include:

• API Server: Introduced the core HTTP server in cmd/api.
• Health Check: Added a /health endpoint for monitoring.
• Configuration: Implemented initial configuration handling.
• Dependency Injection: Set up wire for dependency management.
• OpenAPI Spec: Included the initial openapi.yaml to define the API contract.

^{Description generated by Mesa. Update settings}

[sjmiller609]

I'm not deliberating too much about the exact API fields at the moment, will be changing this as we go. This PR is just setting up boilerplate structure for openAPI code gen, error handling, config, dependency injection, basic testing setup.

[rgarcia]

let's effing go!