Plan specialized result wire encoders

[fulghum]

Plans reusable text and binary result encoders from PostgreSQL field metadata so row scans avoid repeated type resolution and conversion work. Adds specialized float output paths and focused coverage for encoder planning and wire-format behavior.

This is an exploratory performance approach and is intentionally left as a draft while alternative directions are evaluated.

[github-actions]

	Main	PR
Total	42090	42090
Successful	19290	19292
Failures	22800	22798
Partial Successes1	5459	5459

	Main	PR
Successful	45.8304%	45.8351%
Failures	54.1696%	54.1649%

${\color{lightgreen}Progressions (2)}$

aggregates

QUERY: SELECT sum(b) AS avg_431_773 FROM aggtest;

float8

QUERY: SELECT f.f1, exp(ln(f.f1)) AS exp_ln_f1
   FROM FLOAT8_TBL f
   WHERE f.f1 > '0.0';

Footnotes

1. These are tests that we're marking as Successful, however they do not match the expected output in some way. This is due to small differences, such as different wording on the error messages, or the column names being incorrect while the data itself is correct. ↩

[coffeegoddd]

@fulghum DOLT

read_tests	from_latency	to_latency	percent_change
covering_index_scan_postgres	2.43	2.43	0.0
groupby_scan_postgres	75.82	80.03	5.55
index_join_postgres	2.22	2.18	-1.8
index_join_scan_postgres	1.61	1.58	-1.86
index_scan_postgres	467.3	376.49	-19.43
oltp_point_select	0.36	0.36	0.0
oltp_read_only	6.32	6.32	0.0
select_random_points	0.7	0.7	0.0
select_random_ranges	1.01	1.01	0.0
table_scan_postgres	467.3	383.33	-17.97
types_table_scan_postgres	1170.65	977.74	-16.48

write_tests	from_latency	to_latency	percent_change
oltp_delete_insert_postgres	6.67	6.67	0.0
oltp_insert	3.3	3.36	1.82
oltp_read_write	13.22	13.22	0.0
oltp_update_index	3.55	3.55	0.0
oltp_update_non_index	3.25	3.25	0.0
oltp_write_only	6.91	7.04	1.88
types_delete_insert_postgres	7.17	7.17	0.0