feat(updater) support proxy (#891)

* add proxy support

Signed-off-by: San Zhang <sanzhang@mail.com>

* 1. change string to url for proxy type
2. add proxy option in js api

Signed-off-by: San Zhang <sanzhang@mail.com>

* fix fmt issue

Signed-off-by: San Zhang <sanzhang@mail.com>

* Update plugins/updater/guest-js/index.ts

---------

Signed-off-by: San Zhang <sanzhang@mail.com>

plugins/updater/src/commands.rs

@@ -11,6 +11,7 @@ use std::{
     sync::atomic::{AtomicBool, Ordering},
     time::Duration,
 };
+use url::Url;
 
 #[derive(Debug, Serialize)]
 #[serde(tag = "event", content = "data")]
@@ -42,6 +43,7 @@ pub(crate) async fn check<R: Runtime>(
     pending: State<'_, PendingUpdate>,
     headers: Option<Vec<(String, String)>>,
     timeout: Option<u64>,
+    proxy: Option<String>,
     target: Option<String>,
 ) -> Result<Metadata> {
     let mut builder = app.updater_builder();
@@ -53,6 +55,10 @@ pub(crate) async fn check<R: Runtime>(
     if let Some(timeout) = timeout {
         builder = builder.timeout(Duration::from_secs(timeout));
     }
+    if let Some(ref proxy) = proxy {
+        let url = Url::parse(proxy.as_str())?;
+        builder = builder.proxy(url);
+    }
     if let Some(target) = target {
         builder = builder.target(target);
     }