✨ feat(delete): implement batch delete functionality

- add `delete.rs` module for batch deleting messages in gmail
- create `Delete` struct with methods for preparing and executing batch deletes
- implement `batch_delete` method to delete messages using gmail api

src/delete.rs

@@ -0,0 +1,67 @@
+use google_gmail1::api::BatchDeleteMessagesRequest;
+
+use crate::{MessageList, Result};
+
+/// Struct for trashing messages
+#[derive(Debug)]
+pub struct Delete {
+    message_list: MessageList,
+}
+
+impl Delete {
+    /// Create a new Delete struct
+    pub async fn new(credential: &str) -> Result<Self> {
+        let message_list = MessageList::new(credential).await?;
+        Ok(Delete { message_list })
+    }
+
+    /// Set the maximum results
+    pub fn set_max_results(&mut self, value: u32) {
+        self.message_list.set_max_results(value);
+    }
+
+    /// Report the maximum results value
+    pub fn max_results(&self) -> u32 {
+        self.message_list.max_results()
+    }
+
+    /// Add label to the labels collection
+    pub async fn add_labels(&mut self, credential: &str, labels: &[String]) -> Result<()> {
+        self.message_list.add_labels(credential, labels).await
+    }
+
+    /// Set the query string
+    pub fn set_query(&mut self, query: &str) {
+        self.message_list.set_query(query)
+    }
+
+    /// Run the trash cli
+    pub async fn prepare(&mut self, pages: u32) -> Result<()> {
+        self.message_list.run(pages).await
+    }
+
+    /// Run the batch delete on the selected messages
+    pub async fn batch_delete(&self) -> Result<()> {
+        let ids = Some(self.message_list.message_ids());
+
+        let batch_request = BatchDeleteMessagesRequest { ids };
+
+        log::trace!("{batch_request:#?}");
+
+        let _res = self
+            .message_list
+            .hub()
+            .users()
+            .messages_batch_delete(batch_request, "me")
+            .add_scope("https://mail.google.com/")
+            .doit()
+            .await
+            .map_err(Box::new)?;
+
+        for m in self.message_list.messages() {
+            log::info!("Message with subject `{}` deleted.", m.subject());
+        }
+
+        Ok(())
+    }
+}