Add scan plan logic for remote joins

[jnidzwetzki]

This patch adds the missing functionality to create scan plans for remote joins. Most of the code is a backport from PG Upstream.

[nikkhils]

LGTM!

[codecov]

Codecov Report

Merging #5196 (2a042c3) into main (f211294) will decrease coverage by 26.40%.
The diff coverage is 34.61%.

@@             Coverage Diff             @@
##             main    #5196       +/-   ##
===========================================
- Coverage   89.04%   62.64%   -26.40%     
===========================================
  Files         225      225               
  Lines       51752    45396     -6356     
===========================================
- Hits        46084    28440    -17644     
- Misses       5668    16956    +11288     

Impacted Files	Coverage Δ
tsl/src/fdw/fdw.c	51.02% <0.00%> (-43.19%)	⬇️
tsl/src/fdw/scan_plan.c	86.39% <33.33%> (-5.04%)	⬇️
tsl/src/fdw/data_node_scan_plan.c	96.73% <100.00%> (-0.42%)	⬇️
src/chunk.h	0.00% <0.00%> (-100.00%)	⬇️
src/chunk_index.h	0.00% <0.00%> (-100.00%)	⬇️
tsl/src/remote/data_fetcher.h	0.00% <0.00%> (-100.00%)	⬇️
tsl/src/compression/dictionary_hash.h	0.00% <0.00%> (-100.00%)	⬇️
tsl/src/compression/simple8b_rle.h	0.00% <0.00%> (-96.57%)	⬇️
src/scanner.c	0.00% <0.00%> (-94.10%)	⬇️
src/loader/bgw_counter.c	0.00% <0.00%> (-87.04%)	⬇️
... and 204 more

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