[planners] rename ExpressionAction -> Expression

[sundy-li]

Summary

Rename:

1. ExpressionAction --> Expression, because Expression is a modern name for SQL expressions.
2. ActionNode --> ExpressionAction, that's the better name for ExpressionAction

Changelog

• Improvement

Related Issues

Test Plan

Unit Tests
Stateless Tests

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[codecov-commenter]

Codecov Report

Merging #635 (6759f6a) into master (8ed7986) will increase coverage by 0%.
The diff coverage is 81%.

@@          Coverage Diff           @@
##           master    #635   +/-   ##
======================================
  Coverage      80%     80%           
======================================
  Files         286     284    -2     
  Lines       13782   13770   -12     
======================================
- Hits        11094   11085    -9     
+ Misses       2688    2685    -3     

Impacted Files	Coverage Δ
...y/src/pipelines/transforms/transform_expression.rs	75% <ø> (ø)
...rc/pipelines/transforms/transform_groupby_final.rs	80% <ø> (ø)
...y/src/pipelines/transforms/transform_projection.rs	74% <ø> (ø)
...y/src/pipelines/transforms/transform_sort_merge.rs	79% <ø> (ø)
common/planners/src/plan_expression_literal.rs	50% <42%> (ø)
common/planners/src/plan_rewriter.rs	51% <43%> (ø)
.../pipelines/transforms/transform_groupby_partial.rs	78% <50%> (ø)
common/planners/src/plan_expression_chain.rs	37% <63%> (ø)
fusequery/query/src/sql/plan_parser.rs	86% <78%> (+<1%)	⬆️
common/planners/src/plan_expression_visitor.rs	82% <85%> (ø)
... and 32 more

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