Support for text keys in ALTER TABLE statements

[zachmu]

Stacked on top of #1243, relies on dolthub/go-mysql-server#2871

[github-actions]

	Main	PR
covering_index_scan_postgres	387.27/s	389.82/s	+0.6%
index_join_postgres	155.32/s	155.89/s	+0.3%
index_join_scan_postgres	188.19/s	189.01/s	+0.4%
index_scan_postgres	12.64/s	12.63/s	-0.1%
oltp_point_select	2801.60/s	2818.65/s	+0.6%
oltp_read_only	1877.79/s	1881.40/s	+0.1%
select_random_points	113.46/s	113.91/s	+0.3%
select_random_ranges	132.96/s	135.20/s	+1.6%
table_scan_postgres	10.37/s	10.23/s	-1.4%
types_table_scan_postgres	5.43/s	5.54/s	+2.0%

[github-actions]

	Main	PR
Total	42090	42090
Successful	15692	15693
Failures	26398	26397
Partial Successes1	5201	5201

	Main	PR
Successful	37.2820%	37.2844%
Failures	62.7180%	62.7156%

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

create_table_like

QUERY:          CREATE TABLE inhg (LIKE inhx);
RECEIVED ERROR: prefix index on string column 'xx' unsupported (errno 1105) (sqlstate HY000)

${\color{lightgreen}Progressions (3)}$

create_table_like

QUERY: ALTER TABLE inhx ADD PRIMARY KEY (xx);

memoize

QUERY: CREATE INDEX strtest_n_idx ON strtest (n);

publication

QUERY: ALTER TABLE testpub_tbl8_1 ADD PRIMARY KEY (c);

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! No comments!