Add loader support for struct of list/struct/string

[acquamarin]

1. This PR adds loader support for struct of list/struct/string.
2. Refactors the InMemColumnChunk using a hierachy structure.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@6936d8d). Click here to learn what that means.
Patch coverage: 87.87% of modified lines in pull request are covered.

❗ Current head 7c25d12 differs from pull request most recent head 3ae8639. Consider uploading reports for the commit 3ae8639 to get more accurate results

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #1563   +/-   ##
=========================================
  Coverage          ?   91.68%           
=========================================
  Files             ?      699           
  Lines             ?    25218           
  Branches          ?        0           
=========================================
  Hits              ?    23121           
  Misses            ?     2097           
  Partials          ?        0           

Impacted Files	Coverage Δ
src/include/common/types/types.h	100.00% <ø> (ø)
src/include/storage/storage_utils.h	100.00% <ø> (ø)
src/include/storage/wal_replayer_utils.h	100.00% <ø> (ø)
...e/in_mem_storage_structure/in_mem_column_chunk.cpp	79.29% <80.81%> (ø)
...age/in_mem_storage_structure/in_mem_column_chunk.h	93.33% <87.50%> (ø)
src/common/types/types.cpp	91.47% <97.01%> (ø)
src/include/common/string_utils.h	100.00% <100.00%> (ø)
src/include/storage/copier/node_copier.h	93.54% <100.00%> (ø)
...e/storage/in_mem_storage_structure/in_mem_column.h	100.00% <100.00%> (ø)
src/storage/copier/node_copier.cpp	98.29% <100.00%> (ø)
... and 5 more

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