Use `wasm-pkg-tools` to pull interface and world definitions from well-known registries

[`wasm-pkg-tools`](https://github.com/bytecodealliance/wasm-pkg-tools) provides tools for downloading published WIT definitions (in binary form) from registries, including [default registries](https://github.com/bytecodealliance/wasm-pkg-tools#default-fallback-registries). Ideally, if a `componentize-py` user targets a world that's been published to such a registry, e.g. `wasi:cli/command@0.2.0`, they shouldn't need to provide any WIT files (nor, in the case of WASI worlds, even specify the registry). Instead, `componentize-py` should use `wasm-pkg-tools` to query any available registries and download the world and interface definitions automatically.

In short, we should add a new option for specifying one or more registries (and use the default registries otherwise), plus another option to disable using the default registries if desired. I imagine we'll still want to prioritize using local WIT files if provided.

追踪 componentize-py 当前的 WIT 和 world 解析入口，然后检查 wasm-pkg-tools 如何查询默认 registry 和显式提供的 registry。完成的标准是：无需本地 WIT 文件即可解析 wasi:cli/command@0.2.0 等已发布的 world，支持自定义 registry 和禁用默认 registry，并且本地 WIT 文件仍保有优先级；为这些情况添加或运行 coverage。

由索引模型根据 Issue 内容生成。