chore: add metrics for compact and recluster

[zhyass]

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Summary

• new metrics

  • fuse_compact_block_build_lazy_part_milliseconds (histogram)
  • fuse_recluster_build_task_milliseconds (histo)
  • fuse_recluster_segment_nums_scheduled (counter)

• While selecting the blocks with the highest depth

  segments no longer processed one by one, multiple segments might be squashed into one unit for selection, if the number of blocks of these segments reaches the value of setting FUSE_OPT_KEY_BLOCK_PER_SEGMENT.

• tweak(fix) the logic of ReclusterMutator::segment_can_recluster

  the segment will be a candidate for recluster, only if it does not consist of constant blocks(only), or the number of blocks does not reach the value of setting FUSE_OPT_KEY_BLOCK_PER_SEGMENT.

• adjusted log messages for clarity and precision.

• Fixes #[Link the issue here]

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - Explain why

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is 

[dantengsky]

@zhyass PR summary has been updated, please have a look