* Get gc id before index blocks
* Add test gc online
* Add test gc online
* Adjust time of run gc
---------
Co-authored-by: 杨赫然 <heran.yang@seafile.com>
* Add online gc core
* Add check gc when update repo
* Go add check gc when update repo
* Add gc unit test
* Support set pwd_hash for gc and fsck
* Optimize to check if block exists
---------
Co-authored-by: 杨赫然 <heran.yang@seafile.com>