feat(cli): wait for client on create/unlock

This adds logic to wait for the xud client to be ready before attempting
the `CreateNode` or `UnlockNode` calls. These calls may be made shortly
after starting xud - for example as part of a bash script - and this
wait of up to 3 seconds may prevent transient failures or race
conditions.

lib/cli/commands/create.ts

@@ -55,7 +55,11 @@ export const handler = (argv: Arguments) => {
       if (password1 === password2) {
         const request = new CreateNodeRequest();
         request.setPassword(password1);
-        loadXudInitClient(argv).createNode(request, callback(argv, formatOutput));
+        const client = loadXudInitClient(argv);
+        // wait up to 3 seconds for rpc server to listen before call in case xud was just started
+        client.waitForReady(Date.now() + 3000, () => {
+          client.createNode(request, callback(argv, formatOutput));
+        });
       } else {
         console.log('Passwords do not match, please try again.');
       }

lib/cli/commands/unlock.ts

@@ -21,6 +21,10 @@ export const handler = (argv: Arguments) => {
     rl.close();
     const request = new UnlockNodeRequest();
     request.setPassword(password);
-    loadXudInitClient(argv).unlockNode(request, callback(argv));
+    const client = loadXudInitClient(argv);
+    // wait up to 3 seconds for rpc server to listen before call in case xud was just started
+    client.waitForReady(Date.now() + 3000, () => {
+      client.unlockNode(request, callback(argv));
+    });
   });
 };