Encode plan when inserting to dp table

[andyfengHKU]

This PR removes the custom hasher for schema because they are not computational efficient. Instead, we now encode a logical plan's factorization schema into a bitset by considering the flat information of certain expressions. As a consequence

• We improve the computational time of enumeration.
• We reduce the number of plans kept in each subgraph.
• Fewer plans are being generated.

[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.08 ⚠️

Comparison is base (3345cb3) 92.73% compared to head (11910ae) 92.66%.

❗ Current head 11910ae differs from pull request most recent head 90f0f0d. Consider uploading reports for the commit 90f0f0d to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1406      +/-   ##
==========================================
- Coverage   92.73%   92.66%   -0.08%     
==========================================
  Files         642      642              
  Lines       22110    22089      -21     
==========================================
- Hits        20504    20468      -36     
- Misses       1606     1621      +15     

Impacted Files	Coverage Δ
src/binder/query/query_graph.cpp	96.29% <ø> (ø)
.../include/binder/query/reading_clause/query_graph.h	96.66% <ø> (ø)
...ude/planner/logical_plan/logical_operator/schema.h	100.00% <ø> (ø)
src/planner/operator/schema.cpp	70.00% <ø> (-8.73%)	⬇️
src/include/planner/subplans_table.h	100.00% <100.00%> (ø)
src/planner/join_order_enumerator.cpp	98.36% <100.00%> (+<0.01%)	⬆️
src/planner/subplans_table.cpp	100.00% <100.00%> (ø)

... and 14 files with indirect coverage changes

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.