refactor: Restructure project layout and clean up dependencies (#30)

This commit introduces a significant reorganization of the project structure to improve maintainability and clarity.

Key changes include:
- Adjusted the directory layout for a more logical module organization.
- Removed unused crate dependencies, reducing the overall project size and potentially speeding up build times.
- Updated import paths and configuration files to reflect the structural changes.

crates/ecstore/src/bucket/quota/mod.rs

@@ -0,0 +1,52 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use crate::error::Result;
+use rmp_serde::Serializer as rmpSerializer;
+use serde::{Deserialize, Serialize};
+
+// 定义 QuotaType 枚举类型
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum QuotaType {
+    Hard,
+}
+
+// 定义 BucketQuota 结构体
+#[derive(Debug, Deserialize, Serialize, Default, Clone)]
+pub struct BucketQuota {
+    quota: Option<u64>, // 使用 Option 来表示可能不存在的字段
+
+    size: u64,
+
+    rate: u64,
+
+    requests: u64,
+
+    quota_type: Option<QuotaType>,
+}
+
+impl BucketQuota {
+    pub fn marshal_msg(&self) -> Result<Vec<u8>> {
+        let mut buf = Vec::new();
+
+        self.serialize(&mut rmpSerializer::new(&mut buf).with_struct_map())?;
+
+        Ok(buf)
+    }
+
+    pub fn unmarshal(buf: &[u8]) -> Result<Self> {
+        let t: BucketQuota = rmp_serde::from_slice(buf)?;
+        Ok(t)
+    }
+}