[feature](cold-data) move cold data to object storage without losing any feature(BE) (#10280)

This PR supports rowset level data upload on the BE side, so that there can be both cold data and hot data in a tablet,
and there is no necessary to prohibit loading new data to cooled tablets.

Each rowset is bound to a `FileSystem`, so that the storage layer can read and write rowsets without
perceiving the underlying filesystem.

The abstracted `RemoteFileSystem` can try local caching strategies with different granularity,
instead of caching segment files as before.

To avoid conflicts with the code in be/src/io, we temporarily put the file system related code in the be/src/io/fs directory.
In the future, `FileReader`s and `FileWriter`s should be unified.

be/src/runtime/exec_env_init.cpp

@@ -24,6 +24,7 @@
 #include "olap/page_cache.h"
 #include "olap/segment_loader.h"
 #include "olap/storage_engine.h"
+#include "olap/storage_policy_mgr.h"
 #include "runtime/broker_mgr.h"
 #include "runtime/bufferpool/buffer_pool.h"
 #include "runtime/bufferpool/reservation_tracker.h"
@@ -139,6 +140,7 @@ Status ExecEnv::_init(const std::vector<StorePath>& store_paths) {
     _stream_load_executor = new StreamLoadExecutor(this);
     _routine_load_task_executor = new RoutineLoadTaskExecutor(this);
     _small_file_mgr = new SmallFileMgr(this, config::small_file_dir);
+    _storage_policy_mgr = new StoragePolicyMgr();
 
     _backend_client_cache->init_metrics("backend");
     _frontend_client_cache->init_metrics("frontend");