weaken the function of BufferWriteRestoreManager

[jixuan1989]

• remove the field BufferIO from BufferWriteRestoreManager;

After this PR, I will try to merge the two class BufferIO and BufferWriteRestoreManager into one: a TsFileIoWriter which has the ability to restore metadata.

[codecov[bot]]

Codecov Report

Merging #555 into kill_thanos will increase coverage by 3.48%. The diff coverage is 91.2%.

@@               Coverage Diff               @@
##           kill_thanos     #555      +/-   ##
===============================================
+ Coverage        50.59%   54.07%   +3.48%     
===============================================
  Files              416      416              
  Lines            33824    36055    +2231     
  Branches          7595     9914    +2319     
===============================================
+ Hits             17112    19497    +2385     
+ Misses           15261    14891     -370     
- Partials          1451     1667     +216

Impacted Files	Coverage Δ
...nghua/tsfile/write/writer/DefaultTsFileOutput.java	64.28% <0%> (-10.72%)	:arrow_down:
...singhua/iotdb/engine/overflow/ioV2/OverflowIO.java	57.83% <100%> (-13.8%)	:arrow_down:
...u/tsinghua/tsfile/write/writer/TsFileIOWriter.java	94.08% <100%> (+0.61%)	:arrow_up:
...du/tsinghua/iotdb/engine/bufferwrite/BufferIO.java	92.3% <60%> (-7.7%)	:arrow_down:
...iotdb/engine/bufferwrite/BufferWriteProcessor.java	86.2% <87.5%> (+9.28%)	:arrow_up:
.../engine/bufferwrite/BufferWriteRestoreManager.java	96.84% <96.82%> (+0.8%)	:arrow_up:
...u/tsinghua/iotdb/qp/physical/crud/GroupByPlan.java	25% <0%> (-75%)	:arrow_down:
...tsinghua/iotdb/qp/physical/crud/FillQueryPlan.java	33.33% <0%> (-66.67%)	:arrow_down:
...inghua/iotdb/qp/physical/crud/AggregationPlan.java	57.14% <0%> (-42.86%)	:arrow_down:
...ava/cn/edu/tsinghua/iotdb/service/JDBCService.java	50.8% <0%> (-27.95%)	:arrow_down:
... and 104 more

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