feat: remove unnecessary get_piece

[gaius-qi]

Description

This pull request introduces several changes to the dragonfly-client-storage and dragonfly-client projects. The primary focus is on improving the codebase by making function parameters more consistent and adding new methods to check the existence of tasks, persistent cache tasks, and pieces. Additionally, error handling and logging are enhanced in some parts of the code.

Changes related to function parameters:

• dragonfly-client-storage/src/content.rs: Updated hard_link_or_copy_task and hard_link_or_copy_persistent_cache_task methods to take task parameters by reference instead of by value. [1] [2]
• dragonfly-client-storage/src/lib.rs: Updated hard_link_or_copy_task and hard_link_or_copy_persistent_cache_task methods to take task parameters by reference. [1] [2]
• dragonfly-client/src/grpc/dfdaemon_download.rs: Updated multiple methods in DfdaemonDownloadServerHandler to take task parameters by reference. [1] [2] [3] [4]
• dragonfly-client/src/grpc/dfdaemon_upload.rs: Updated multiple methods in DfdaemonUploadServerHandler to take task parameters by reference. [1] [2] [3] [4]
• dragonfly-client/src/resource/persistent_cache_task.rs: Updated multiple methods in PersistentCacheTask to take task parameters by reference. [1] [2] [3] [4] [5] [6] [7] [8]

New methods for checking existence:

• dragonfly-client-storage/src/lib.rs: Added is_task_exists, is_persistent_cache_task_exists, and is_piece_exists methods in Storage to check if tasks, persistent cache tasks, and pieces exist, respectively. [1] [2] [3]
• dragonfly-client-storage/src/metadata.rs: Added corresponding methods in Metadata to support the existence checks. [1] [2] [3]
• dragonfly-client-storage/src/storage_engine/mod.rs: Added is_exist method to the Operations trait to check if an object exists by key.
• dragonfly-client-storage/src/storage_engine/rocksdb.rs: Implemented the is_exist method for RocksdbStorageEngine.

Error handling improvements:

• dragonfly-client/src/resource/piece.rs: Enhanced error handling and logging in the download_piece_from_remote_peer_finished and download_piece_from_source_finished methods. [1] [2]

Related Issue

Motivation and Context

Screenshots (if appropriate)

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 21 lines in your changes missing coverage. Please review.

Project coverage is 34.30%. Comparing base (62c62f7) to head (ddc3d0b).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
dragonfly-client/src/resource/task.rs	0.00%	6 Missing ⚠️
dragonfly-client/src/grpc/dfdaemon_download.rs	0.00%	4 Missing ⚠️
dragonfly-client/src/grpc/dfdaemon_upload.rs	0.00%	4 Missing ⚠️
dragonfly-client-storage/src/lib.rs	0.00%	3 Missing ⚠️
dragonfly-client-storage/src/metadata.rs	0.00%	3 Missing ⚠️
...onfly-client-storage/src/storage_engine/rocksdb.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #869      +/-   ##
==========================================
+ Coverage   33.19%   34.30%   +1.10%     
==========================================
  Files          57       57              
  Lines        8788     8883      +95     
==========================================
+ Hits         2917     3047     +130     
+ Misses       5871     5836      -35     

Files with missing lines	Coverage Δ
dragonfly-client-storage/src/content.rs	3.30% <ø> (ø)
dragonfly-client-storage/src/storage_engine/mod.rs	100.00% <ø> (ø)
...onfly-client/src/resource/persistent_cache_task.rs	0.00% <ø> (ø)
dragonfly-client/src/resource/piece.rs	58.21% <ø> (+7.01%)	⬆️
...onfly-client-storage/src/storage_engine/rocksdb.rs	50.00% <0.00%> (-0.95%)	⬇️
dragonfly-client-storage/src/lib.rs	2.00% <0.00%> (-0.13%)	⬇️
dragonfly-client-storage/src/metadata.rs	58.63% <0.00%> (-0.72%)	⬇️
dragonfly-client/src/grpc/dfdaemon_download.rs	0.00% <0.00%> (ø)
dragonfly-client/src/grpc/dfdaemon_upload.rs	0.00% <0.00%> (ø)
dragonfly-client/src/resource/task.rs	0.00% <0.00%> (ø)

... and 1 file with indirect coverage changes

[chlins]

lgtm