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/object_lock/objectlock_sys.rs

@@ -0,0 +1,67 @@
+// 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 std::sync::Arc;
+use time::OffsetDateTime;
+
+use s3s::dto::{DefaultRetention, ObjectLockLegalHoldStatus, ObjectLockRetentionMode};
+
+use crate::bucket::metadata_sys::get_object_lock_config;
+use crate::store_api::ObjectInfo;
+
+use super::objectlock;
+
+pub struct BucketObjectLockSys {}
+
+impl BucketObjectLockSys {
+    #[allow(clippy::new_ret_no_self)]
+    pub async fn new() -> Arc<Self> {
+        Arc::new(Self {})
+    }
+
+    pub async fn get(bucket: &str) -> Option<DefaultRetention> {
+        if let Ok(object_lock_config) = get_object_lock_config(bucket).await {
+            if let Some(object_lock_rule) = object_lock_config.0.rule {
+                return object_lock_rule.default_retention;
+            }
+        }
+        None
+    }
+}
+
+pub fn enforce_retention_for_deletion(obj_info: &ObjectInfo) -> bool {
+    if obj_info.delete_marker {
+        return false;
+    }
+
+    let lhold = objectlock::get_object_legalhold_meta(obj_info.user_defined.clone());
+    match lhold.status {
+        Some(st) if st.as_str() == ObjectLockLegalHoldStatus::ON => {
+            return true;
+        }
+        _ => (),
+    }
+
+    let ret = objectlock::get_object_retention_meta(obj_info.user_defined.clone());
+    match ret.mode {
+        Some(r) if (r.as_str() == ObjectLockRetentionMode::COMPLIANCE || r.as_str() == ObjectLockRetentionMode::GOVERNANCE) => {
+            let t = objectlock::utc_now_ntp();
+            if OffsetDateTime::from(ret.retain_until_date.expect("err!")).unix_timestamp() > t.unix_timestamp() {
+                return true;
+            }
+        }
+        _ => (),
+    }
+    false
+}