Refine the context functions

[BohuTANG]

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Summary

Summary about this PR:

Part of #3740 , only names changed.

1. Simple get_user_manager()
2. Rename get_data_accessor -> get_storage_accessor
3. Rename get_table_cache -> get_storage_cache

Changelog

• Improvement

Related Issues

Part of #3740

Test Plan

Unit Tests

Stateless Tests

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[codecov-commenter]

Codecov Report

Merging #3753 (213916a) into main (a019084) will decrease coverage by 0%.
The diff coverage is 84%.

@@          Coverage Diff          @@
##            main   #3753   +/-   ##
=====================================
- Coverage     59%     59%   -1%     
=====================================
  Files        707     707           
  Lines      38206   38206           
=====================================
- Hits       22808   22785   -23     
- Misses     15398   15421   +23     

Impacted Files	Coverage Δ
query/src/api/rpc/flight_service.rs	52% <0%> (ø)
...ery/src/interpreters/interpreter_describe_stage.rs	96% <ø> (ø)
query/src/interpreters/interpreter_kill.rs	0% <0%> (ø)
query/src/interpreters/interpreter_show_grants.rs	0% <ø> (ø)
...src/interpreters/plan_schedulers/plan_scheduler.rs	32% <0%> (ø)
.../src/pipelines/transforms/transform_create_sets.rs	0% <0%> (ø)
query/src/storages/system/processes_table.rs	25% <0%> (+<1%)	⬆️
query/src/sql/statements/analyzer_expr.rs	68% <50%> (ø)
query/src/storages/fuse/operations/optimize.rs	92% <85%> (+<1%)	⬆️
query/src/api/rpc/flight_dispatcher.rs	84% <100%> (ø)
... and 27 more

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[BohuTANG]

Only function name changed, let's merge.