Support for UDFs with RETURNS TABLE

[fulghum]

No description provided.

[github-actions]

	Main	PR
covering_index_scan_postgres	526.41/s	532.48/s	+1.1%
index_join_postgres	140.42/s	139.22/s	-0.9%
index_join_scan_postgres	252.07/s	253.77/s	+0.6%
index_scan_postgres	12.91/s	13.16/s	+1.9%
oltp_point_select	2550.22/s	2529.96/s	-0.8%
oltp_read_only	2006.95/s	1967.38/s	-2.0%
select_random_points	129.80/s	132.11/s	+1.7%
select_random_ranges	424.40/s	428.50/s	+0.9%
table_scan_postgres	12.71/s	12.79/s	+0.6%
types_table_scan_postgres	5.90/s	6.06/s	+2.7%

[github-actions]

	Main	PR
Total	42090	42090
Successful	17559	17558
Failures	24531	24532
Partial Successes1	5584	5583

	Main	PR
Successful	41.7177%	41.7154%
Failures	58.2823%	58.2846%

${\color{red}Regressions (1)}$

rangefuncs

QUERY:          SELECT * FROM rngfunc() GROUP BY 1;
RECEIVED ERROR: expected []RecordValue, but got string (errno 1105) (sqlstate HY000)

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. ↩