[ISSUE #6633] Not clear uninitialized files and fix metadata recover

[lizhimins]

Which Issue(s) This PR Fixes

这个提交是对分级存储实现的一些细节改进

1. 清理文件时不清理未初始化的文件。
2. 简化 recover 流程中元数据的加载

Fixes #6633

Brief Description

How Did You Test This Change?

[dingshuangxi888]

LGTM

[codecov-commenter]

Codecov Report

Merging #7342 (a7d55ec) into develop (e11e294) will decrease coverage by 0.02%.
Report is 8 commits behind head on develop.
The diff coverage is 66.66%.

@@              Coverage Diff              @@
##             develop    #7342      +/-   ##
=============================================
- Coverage      42.69%   42.67%   -0.02%     
+ Complexity      9474     9472       -2     
=============================================
  Files           1152     1150       -2     
  Lines          82721    82743      +22     
  Branches       10781    10786       +5     
=============================================
- Hits           35315    35312       -3     
- Misses         42997    43012      +15     
- Partials        4409     4419      +10     

Files Changed	Coverage Δ
...cketmq/tieredstore/file/TieredFlatFileManager.java	51.41% <0.00%> (+0.28%)	⬆️
...ache/rocketmq/tieredstore/file/TieredFlatFile.java	79.34% <90.90%> (+0.93%)	⬆️

... and 48 files with indirect coverage changes

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