[store] feature: reopen a MetaStore

[drmingdrmer]

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Summary

[store] refactor: clean up todo

[store] feature: reopen a MetaStore

MetaStore is the store of a raft node.
In this commit it oly impl RaftState reopen. Log and state machine are
still pure in-memory impl.

Changelog

• New Feature

• Improvement

Related Issues

#271

[databend-bot]

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[codecov-commenter]

Codecov Report

Merging #1066 (bc1117e) into master (2fbe079) will increase coverage by 4%.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           master   #1066     +/-   ##
========================================
+ Coverage      58%     62%     +4%     
========================================
  Files         410     391     -19     
  Lines       21832   20299   -1533     
========================================
- Hits        12777   12773      -4     
+ Misses       9055    7526   -1529     

Impacted Files	Coverage Δ
fusestore/store/src/meta_service/raftmeta.rs	0% <ø> (ø)
common/runtime/src/runtime_test.rs	66% <0%> (-27%)	⬇️
fusestore/store/src/configs/config.rs	0% <0%> (ø)
fusestore/store/src/api/rpc_service.rs	0% <0%> (ø)
fusestore/store/src/meta_service/raft_state.rs	0% <0%> (ø)
fusestore/store/src/meta_service/state_machine.rs	0% <0%> (ø)
fusestore/store/src/meta_service/applied_state.rs
fusestore/store/src/executor/meta_handlers.rs
fusestore/store/src/meta_service/placement.rs
... and 18 more

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[ariesdevil]

LGTM

[databend-bot]

CI Passed
Reviewer Approved
Let's Merge

[drmingdrmer]

LGTM

Thank you man!