feat: support bucket tagging

Closes #41
Signed-off-by: bestgopher <84328409@qq.com>

ecstore/src/bucket_meta.rs

@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use rmp_serde::Serializer;
 use serde::{Deserialize, Serialize};
 use time::OffsetDateTime;
@@ -15,6 +17,9 @@ pub struct BucketMetadata {
     format: u16,
     version: u16,
     pub name: String,
+    #[serde(skip_serializing_if = "Option::is_none", default)]
+    pub tagging: Option<HashMap<String, String>>,
+    #[serde(skip_serializing_if = "Option::is_none", default)]
     pub created: Option<OffsetDateTime>,
 }
 
@@ -54,4 +59,8 @@ impl BucketMetadata {
 
         Ok(buf)
     }
+
+    pub fn unmarshal_from(buffer: &[u8]) -> Result<Self> {
+        Ok(rmp_serde::from_slice(buffer)?)
+    }
 }

ecstore/src/lib.rs

@@ -1,4 +1,4 @@
-mod bucket_meta;
+pub mod bucket_meta;
 mod chunk_stream;
 pub mod disk;
 pub mod disks_layout;