[Consistency Protocol] EC support

[ilixiaocui]

Currently curve has file storage and block storage, but no object storage. Object storage generally needs to support EC, so the community started a discussion here, how curve supports the EC protocol.

An initial idea from fast-2020: Can CRaft fall into engineering practice?

[zhanghuidinah]

/cc @hzh0425

[hzh0425]

We hope to design an independent EC replication system that can coexist with the original Raft system

[Tangruilin]

I agree with @hzh0425
For EC, different CS will storage different data, which is different from raft. If we need to implement ECraft, the RaftLog may required a lot change

[WyattJia]

Looking forward to further progress.