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/s3select-query/src/execution/scheduler/local.rs

@@ -0,0 +1,36 @@
+// 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 async_trait::async_trait;
+use datafusion::error::DataFusionError;
+use datafusion::execution::context::TaskContext;
+use datafusion::physical_plan::{ExecutionPlan, execute_stream};
+use rustfs_s3select_api::query::scheduler::{ExecutionResults, Scheduler};
+
+pub struct LocalScheduler {}
+
+#[async_trait]
+impl Scheduler for LocalScheduler {
+    async fn schedule(
+        &self,
+        plan: Arc<dyn ExecutionPlan>,
+        context: Arc<TaskContext>,
+    ) -> Result<ExecutionResults, DataFusionError> {
+        let stream = execute_stream(plan, context)?;
+
+        Ok(ExecutionResults::new(stream))
+    }
+}

crates/s3select-query/src/execution/scheduler/mod.rs

@@ -0,0 +1,15 @@
+// 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.
+
+pub mod local;