[ENH] Add OpenAPI spec to Rust server (chroma-core#3815)

## Description of changes

 - Improvements & Bug fixes
   - Updates `axum` to `0.8`
 - New functionality
   - Adds `/openapi.json` route that renders an OpenAPI spec
   - Adds `/docs/` route that renders Swagger
- Adds code generation of OpenAPI spec with
[`utoipa`](https://github.com/juhaku/utoipa)
- Standardizes path params to be `tenant` (*not tenant_id*) and
`database` (*not database_name*)

Here's a video demo of how it works:


https://github.com/user-attachments/assets/e66d9fc0-8b8b-408f-8b3a-2e975646edf3

Notes:
* The routes and basic functionality mirror current Python functionality
(see: https://api.trychroma.com:8000/docs)
* OpenAPI spec is substantially improved, including: typed errors, typed
responses, security headers

Author: philipithomas

Cargo.lock

@@ -6,7 +6,7 @@ members = ["rust/benchmark", "rust/blockstore", "rust/cache", "rust/chroma", "ru
 [workspace.dependencies]
 arrow = "52.2.0"
 async-trait = "0.1"
-axum = { version = "0.7", features = ["macros"] }
+axum = { version = "0.8", features = ["macros"] }
 chrono = { version = "0.4", features = ["serde"] }
 clap = { version = "4", features = ["derive"] }
 criterion = { version = "0.5", features = ["async_tokio"] }
@@ -38,6 +38,7 @@ tracing-bunyan-formatter = "0.3"
 tracing-opentelemetry = "0.28.0"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 uuid = { version = "1.11.0", features = ["v4", "fast-rng", "macro-diagnostics", "serde"] }
+utoipa = { version = "5.0.0", features = ["macros", "axum_extras", "debug", "uuid"] }
 sqlx = { version = "0.8.3", features = ["runtime-tokio", "sqlite"] }
 sha2 = "0.10.8"
 md5 = "0.7.0"

Cargo.toml

@@ -42,3 +42,6 @@ chroma-system = { workspace = true }
 chroma-tracing = { workspace = true }
 chroma-types = { workspace = true }
 chroma-sqlite = { workspace = true }
+utoipa = { workspace = true }
+utoipa-axum = { version = "0.2.0", features = ["debug"] }
+utoipa-swagger-ui = { version = "9", features = ["axum"] }