wollet: add EsploraClient::set_waterfalls_server_recipient

some setups may re-create the client, causing every time to ask the
static server recipient to encrypt descriptors. By allowing a method to
set it clients can avoid that roundtrip.

lwk_wasm/src/esplora.rs

@@ -1,5 +1,5 @@
 use crate::{Error, Network, Pset, Txid, Update, Wollet};
-use lwk_wollet::clients::asyncr;
+use lwk_wollet::{age, clients::asyncr};
 use wasm_bindgen::prelude::*;
 
 /// Wrapper of [`asyncr::EsploraClient`]
@@ -28,6 +28,14 @@ impl EsploraClient {
         let txid = self.inner.broadcast(&(tx.into())).await?;
         Ok(txid.into())
     }
+
+    pub async fn set_waterfalls_server_recipient(&mut self, recipient: &str) -> Result<(), Error> {
+        let recipient: age::x25519::Recipient = recipient
+            .parse()
+            .map_err(|e: &str| Error::Generic(e.to_string()))?;
+        self.inner.set_waterfalls_server_recipient(recipient);
+        Ok(())
+    }
 }
 
 #[cfg(all(test, target_arch = "wasm32"))]

lwk_wollet/src/clients/asyncr/esplora.rs

@@ -432,6 +432,10 @@ impl EsploraClient {
         self.waterfalls_avoid_encryption = true;
     }
 
+    pub fn set_waterfalls_server_recipient(&mut self, recipient: Recipient) {
+        self.waterfalls_server_recipient = Some(recipient);
+    }
+
     async fn download_txs(
         &self,
         history_txs_id: &HashSet<Txid>,

lwk_wollet/src/clients/blocking/esplora.rs

@@ -47,6 +47,10 @@ impl EsploraClient {
     pub fn waterfalls_server_recipient(&mut self) -> Result<Recipient, Error> {
         self.rt.block_on(self.client.waterfalls_server_recipient())
     }
+
+    pub fn set_waterfalls_server_recipient(&mut self, recipient: Recipient) {
+        self.client.set_waterfalls_server_recipient(recipient);
+    }
 }
 
 impl BlockchainBackend for EsploraClient {