feat: add Mihomo API modules and manager (#2869)

• Introduce new API caller implementations for Mihomo in model and module layers.
• Add configuration and API integration files under /src-tauri/src/config/api and /src-tauri/src/model/api.
• Implement a singleton MihomoAPICaller with async API call support and integration tests.
• Create a new MihomoManager module to refresh and fetch proxies from the API.
• Update Cargo.lock and Cargo.toml with additional dependencies (async-trait, env_logger, mockito, tempfile, etc.) related to the Mihomo API support.

src-tauri/src/model/api/mihomo.rs

@@ -0,0 +1,5 @@
+use super::common::ApiCaller;
+
+pub struct MihomoAPICaller {
+    pub(crate) caller: ApiCaller<'static>,
+}