feat: union ops

[universalmind303]

adds the following to both dataframe and sql

• union (distinct union)
• union_all
• union_by_name (distinct union by name)
• union_all_by_name

closes #3855

[codecov]

Codecov Report

Attention: Patch coverage is 89.13043% with 15 lines in your changes missing coverage. Please review.

Project coverage is 78.42%. Comparing base (cf8cc14) to head (dfac4b2).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/daft-logical-plan/src/ops/set_operations.rs	83.11%	13 Missing ⚠️
src/daft-connect/src/spark_analyzer.rs	85.71%	1 Missing ⚠️
src/daft-logical-plan/src/logical_plan.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3872      +/-   ##
==========================================
+ Coverage   78.34%   78.42%   +0.07%     
==========================================
  Files         763      763              
  Lines       96742    96831      +89     
==========================================
+ Hits        75796    75935     +139     
+ Misses      20946    20896      -50     

Files with missing lines	Coverage Δ
daft/dataframe/dataframe.py	85.25% <100.00%> (+0.22%)	⬆️
daft/logical/builder.py	92.02% <100.00%> (+0.12%)	⬆️
src/daft-logical-plan/src/builder/mod.rs	88.79% <100.00%> (+0.90%)	⬆️
src/daft-sql/src/planner.rs	82.27% <100.00%> (+1.77%)	⬆️
src/daft-connect/src/spark_analyzer.rs	77.92% <85.71%> (+0.17%)	⬆️
src/daft-logical-plan/src/logical_plan.rs	74.36% <0.00%> (+0.21%)	⬆️
src/daft-logical-plan/src/ops/set_operations.rs	79.48% <83.11%> (+8.14%)	⬆️

... and 6 files with indirect coverage changes