Change npy reader to read multiple files at one time

[ray6080]

This PR separates some changes from node-group branch.

• NPY reader takes multiple files and read in tandem as record batch instead of read one file at a time.
• Some code cleanup and renaming.

[codecov]

Codecov Report

Patch coverage: 98.73% and project coverage change: -0.04 ⚠️

Comparison is base (60b21ca) 91.32% compared to head (d2846de) 91.29%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1842      +/-   ##
==========================================
- Coverage   91.32%   91.29%   -0.04%     
==========================================
  Files         794      792       -2     
  Lines       28819    28762      -57     
==========================================
- Hits        26320    26258      -62     
- Misses       2499     2504       +5     

Impacted Files	Coverage Δ
src/catalog/catalog.cpp	90.47% <ø> (-0.11%)	⬇️
src/include/catalog/catalog.h	100.00% <ø> (ø)
src/include/processor/operator/copy/read_file.h	100.00% <ø> (ø)
src/include/storage/copier/read_file_state.h	100.00% <ø> (ø)
...rc/include/storage/storage_structure/in_mem_file.h	100.00% <ø> (ø)
src/include/storage/store/rel_table.h	100.00% <ø> (ø)
src/planner/planner.cpp	96.21% <ø> (-0.06%)	⬇️
src/storage/copier/npy_reader.cpp	90.90% <92.85%> (+0.23%)	⬆️
src/binder/bind/bind_copy.cpp	85.71% <100.00%> (ø)
...anner/logical_plan/logical_operator/logical_copy.h	100.00% <100.00%> (ø)
... and 20 more

... and 2 files with indirect coverage changes

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