chore(bridge-withdrawer): better grpc client construction (#1528)

## Summary
Added error context to sequencer GRPC client construction.

## Background
https://github.com/astriaorg/astria/pull/1510/files#r1766478324

## Changes
- Added helper function for constructing the sequencer GRPC client and
switched from using `Endpoint::new()` to `connect_lazy()`.
- Added error context to sequencer GRPC client construction.

## Testing
Passing all tests

## Related Issues
closes #1527
closes #1542

crates/astria-bridge-withdrawer/src/bridge_withdrawer/mod.rs

@@ -4,7 +4,7 @@ use std::{
     time::Duration,
 };
 
-use astria_core::generated::sequencerblock::v1alpha1::sequencer_service_client;
+use astria_core::generated::sequencerblock::v1alpha1::sequencer_service_client::SequencerServiceClient;
 use astria_eyre::eyre::{
     self,
     WrapErr as _,
@@ -15,6 +15,7 @@ use axum::{
     Server,
 };
 use ethereum::watcher::Watcher;
+use http::Uri;
 use hyper::server::conn::AddrIncoming;
 use startup::Startup;
 use tokio::{
@@ -93,10 +94,10 @@ impl BridgeWithdrawer {
             .parse()
             .wrap_err("failed to parse sequencer bridge address")?;
 
-        let sequencer_grpc_connection =
-            tonic::transport::Endpoint::new(sequencer_grpc_endpoint)?.connect_lazy();
-        let sequencer_grpc_client =
-            sequencer_service_client::SequencerServiceClient::new(sequencer_grpc_connection);
+        let sequencer_grpc_client = connect_sequencer_grpc(&sequencer_grpc_endpoint)
+            .wrap_err_with(|| {
+                format!("failed to connect to Sequencer over gRPC at `{sequencer_grpc_endpoint}`")
+            })?;
         let sequencer_cometbft_client =
             sequencer_client::HttpClient::new(&*sequencer_cometbft_endpoint)
                 .wrap_err("failed constructing cometbft http client")?;
@@ -466,3 +467,14 @@ pub(crate) fn flatten_result<T>(res: Result<eyre::Result<T>, JoinError>) -> eyre
         Err(err) => Err(err).wrap_err("task panicked"),
     }
 }
+
+fn connect_sequencer_grpc(
+    sequencer_grpc_endpoint: &str,
+) -> eyre::Result<SequencerServiceClient<tonic::transport::Channel>> {
+    let uri: Uri = sequencer_grpc_endpoint
+        .parse()
+        .wrap_err("failed to parse endpoint as URI")?;
+    Ok(SequencerServiceClient::new(
+        tonic::transport::Endpoint::from(uri).connect_lazy(),
+    ))
+}