pgsql: Add test coverage for indirection transformation

Add test coverage for indirection transformation

These tests cover nested arrays of composite data types,
single-argument functions, and casting using dot-notation, providing a
baseline for future enhancements to jsonb dot-notation support.

Author: Alexandra Wang <alexandra(dot)wang(dot)oss(at)gmail(dot)com>
Reviewed-by: Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com>
Discussion: https://www.postgresql.org/message-id/flat/CAK98qZ1JNNAx4QneJG+eX7iLesOhd6A68FNQVvvHP6Up_THf3A(at)mail(dot)gmail(dot)com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/64492917280a1f6227ed9cf43d39095e2cec5cab

Modified Files
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src/test/regress/expected/arrays.out | 26 +++++++++--
src/test/regress/expected/jsonb.out | 88 ++++++++++++++++++++++++++++++++++++
src/test/regress/sql/arrays.sql | 7 ++-
src/test/regress/sql/jsonb.sql | 18 ++++++++
4 files changed, 132 insertions(+), 7 deletions(-)