Write `get-file` and commands to get the list of blocks from another node

Description

This closes #1 (closed) by providing an API that allows to get a file with just its hash

Detailed list of changes

• add get_file, get_blocks_info_from and other things related to managing the filesystem
• add new commands to nu API
• remove DragoonBehaviour as it was not useful
• add two new tests for get_file and change the already existing test to use the new API

Note

The get_file is still very rough, the error management needs to be handled better to take into a lot more cases of failure

src/dragoon_network.rs

@@ -795,6 +795,15 @@ where
         }
     }
 
+    async fn get_providers(&mut self, key: String, sender: Sender<Vec<PeerId>>) {
+        let query_id = self
+            .swarm
+            .behaviour_mut()
+            .kademlia
+            .get_providers(key.into_bytes().into());
+        self.pending_get_providers.insert(query_id, sender);
+    }
+
     async fn bootstrap(&mut self) -> Result<()> {
         match self.swarm.behaviour_mut().kademlia.bootstrap() {
             Ok(_) => Ok(()),
@@ -820,17 +829,17 @@ where
     }
 
     async fn get_block_list(&mut self, file_hash: String) -> Result<Vec<String>> {
-        let block_path = self.get_block_dir(file_hash);
+        let block_path = self.get_block_dir(file_hash.clone());
         let mut block_names = vec![];
         let mut dir_entry = tfs::read_dir(block_path).await?;
         while let Some(entry) = dir_entry.next_entry().await? {
             block_names.push(entry.file_name().into_string().map_err(
                 |os_string| -> anyhow::Error {
                     anyhow::anyhow!(
-                        "Could not convert the os string {:?} as a valid String",
-                        os_string
+                        "Could not convert the os string {:?} as a valid String for file {}",
+                        os_string,
+                        file_hash,
                     )
-                    .into()
                 },
             )?);
         }