feat: add proxy to electrum and esplora

Author: reez

bdk-ffi/src/bdk.udl

@@ -921,7 +921,8 @@ interface Descriptor {
 /// cache to avoid re-fetching already downloaded transactions.
 interface EsploraClient {
   /// Creates a new bdk client from a esplora_client::BlockingClient
-  constructor(string url);
+  /// Optional: Set the proxy of the builder
+  constructor(string url, optional string? proxy = null);
 
   /// Scan keychain scripts for transactions against Esplora, returning an update that can be
   /// applied to the receiving structures.
@@ -979,8 +980,9 @@ interface EsploraClient {
 /// cache to avoid re-fetching already downloaded transactions.
 interface ElectrumClient {
   /// Creates a new bdk client from a electrum_client::ElectrumApi
+  /// Optional: Set the proxy of the builder
   [Throws=ElectrumError]
-  constructor(string url);
+  constructor(string url, optional string? proxy = null);
 
   /// Full scan the keychain scripts specified with the blockchain (via an Electrum client) and
   /// returns updates for bdk_chain data structures.

bdk-ffi/src/electrum.rs

@@ -25,9 +25,15 @@ use std::sync::Arc;
 pub struct ElectrumClient(BdkBdkElectrumClient<bdk_electrum::electrum_client::Client>);
 
 impl ElectrumClient {
-    pub fn new(url: String) -> Result<Self, ElectrumError> {
-        let inner_client: bdk_electrum::electrum_client::Client =
-            bdk_electrum::electrum_client::Client::new(url.as_str())?;
+    pub fn new(url: String, proxy: Option<String>) -> Result<Self, ElectrumError> {
+        let mut config = bdk_electrum::electrum_client::ConfigBuilder::new();
+        if let Some(proxy) = proxy {
+            config = config.socks5(Some(bdk_electrum::electrum_client::Socks5Config::new(
+                proxy.as_str(),
+            )));
+        }
+        let inner_client =
+            bdk_electrum::electrum_client::Client::from_config(url.as_str(), config.build())?;
         let client = BdkBdkElectrumClient::new(inner_client);
         Ok(Self(client))
     }

bdk-ffi/src/esplora.rs

@@ -23,9 +23,12 @@ use std::sync::Arc;
 pub struct EsploraClient(BlockingClient);
 
 impl EsploraClient {
-    pub fn new(url: String) -> Self {
-        let client = Builder::new(url.as_str()).build_blocking();
-        Self(client)
+    pub fn new(url: String, proxy: Option<String>) -> Self {
+        let mut builder = Builder::new(url.as_str());
+        if let Some(proxy) = proxy {
+            builder = builder.proxy(proxy.as_str());
+        }
+        Self(builder.build_blocking())
     }
 
     pub fn full_scan(