bug fix for column defaults with function values

[zachmu]

Removed the GMS validateColumnDefaults rule in favor of our own, and also made it run on CreateTable statements (it wasn't before due to an oversight in a type assertion).

Also implemented the gen_random_uuid function.

[github-actions]

	Main	PR
covering_index_scan_postgres	377.55/s	359.04/s	-5.0%
index_join_postgres	153.32/s	152.90/s	-0.3%
index_join_scan_postgres	183.67/s	183.58/s	-0.1%
index_scan_postgres	12.62/s	12.80/s	+1.4%
oltp_point_select	2746.43/s	2766.41/s	+0.7%
oltp_read_only	1867.75/s	1875.51/s	+0.4%
select_random_points	111.00/s	112.77/s	+1.5%
select_random_ranges	132.42/s	132.50/s	0.0%
table_scan_postgres	12.01/s	12.00/s	-0.1%
types_table_scan_postgres	5.61/s	5.68/s	+1.2%

[github-actions]

	Main	PR
Total	42090	42090
Successful	15531	15531
Failures	26559	26559
Partial Successes1	5224	5224

	Main	PR
Successful	36.8995%	36.8995%
Failures	63.1005%	63.1005%

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. ↩

[Hydrocharged]

LGTM!