SESSIONS-3933: Refine the file and field name

[BohuTANG]

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Summary

Summary about this PR:

• rename query/src/sessions/{context.rs => query_ctx.rs} (97%)
• rename query/src/sessions/{context_shared.rs => query_ctx_shared.rs} (99%)
• rename query/src/sessions/{session_status.rs => session_ctx.rs} (97%)
• rename query/src/sessions/{sessions.rs => session_mgr.rs} (97%)
• delete mode 100644 query/src/sessions/sessions_info.rs, move to sessions_mgr.rs
• Rename MutableStatus to SessionContext

Changelog

• Improvement

Related Issues

Patch-1 of #3933

Test Plan

Unit Tests

Stateless Tests

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[codecov-commenter]

Codecov Report

Merging #4015 (dbd85f0) into main (845b811) will decrease coverage by 0%.
The diff coverage is 77%.

@@          Coverage Diff           @@
##            main   #4015    +/-   ##
======================================
- Coverage     57%     57%    -1%     
======================================
  Files        806     811     +5     
  Lines      43170   43310   +140     
======================================
+ Hits       24703   24719    +16     
- Misses     18467   18591   +124     

Impacted Files	Coverage Δ
common/meta/sled-store/src/sled_serde.rs	100% <ø> (ø)
query/src/interpreters/interpreter_copy.rs	0% <0%> (ø)
common/dal2/src/services/s3.rs	22% <10%> (-47%)	⬇️
common/dal2/src/ops/header.rs	75% <75%> (ø)
common/dal2/src/ops/stat.rs	77% <75%> (ø)
common/dal2/src/readers/stream.rs	75% <75%> (ø)
common/dal2/src/ops/delete.rs	87% <85%> (ø)
common/dal2/src/readers/seekable.rs	97% <97%> (ø)
common/dal2/src/operator.rs	100% <100%> (ø)
common/dal2/src/ops/read.rs	94% <100%> (ø)
... and 14 more

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