✨ feat(list): implement list api to retrieve gmail messages

- add list struct to encapsulate gmail api connection
- implement run function to execute the api call and handle potential errors

src/list.rs

@@ -1 +1,38 @@
+use google_gmail1::{
+    Error, Gmail, hyper_rustls::HttpsConnector, hyper_util::client::legacy::connect::HttpConnector,
+};
 
+/// Struct to capture configuration for List API call.
+pub struct List {
+    hub: Gmail<HttpsConnector<HttpConnector>>,
+}
+
+impl List {
+    /// Create a new List struct and add the Gmail api connection.
+    pub fn new(hub: Gmail<HttpsConnector<HttpConnector>>) -> Self {
+        List { hub }
+    }
+
+    /// Run the Gmail api as configured
+    pub async fn run(&self) {
+        let result = self.hub.users().messages_list("me").doit().await;
+
+        match result {
+            Err(e) => match e {
+                // The Error enum provides details about what exactly happened.
+                // You can also just use its `Debug`, `Display` or `Error` traits
+                Error::HttpError(_)
+                | Error::Io(_)
+                | Error::MissingAPIKey
+                | Error::MissingToken(_)
+                | Error::Cancelled
+                | Error::UploadSizeLimitExceeded(_, _)
+                | Error::Failure(_)
+                | Error::BadRequest(_)
+                | Error::FieldClash(_)
+                | Error::JsonDecodeError(_, _) => println!("{e}"),
+            },
+            Ok(res) => println!("Success: {res:?}"),
+        }
+    }
+}