Projections on vector indexes incorrectly erased in GMS in-memory database

[nicktobey]

This appears to only affect the GMS in-memory database that we use for tests, and does not appear to affect Dolt itself.

CREATE TABLE comp_vector_index_t0 (pk BIGINT PRIMARY KEY, v1 BIGINT, json_column JSON NOT NULL, vector_column VECTOR(2) NOT NULL GENERATED ALWAYS AS (STRING_TO_VECTOR(json_column)) STORED);
INSERT INTO comp_vector_index_t0 (pk, v1, json_column) VALUES (0,0,"[3,16]"),(1,2,"[65,9]"),(2,3,"[38,37]"),(3,3,"[99,99]"),(4,5,"[17,42]"),(5,6,"[6,76]"),(6,6,"[81,33]"), (7,7,"[33,51]"),(8,7,"[37,42]");
select pk, json_column from comp_vector_index_t0 order by vec_distance('[50,50]', json_column) limit 5

Expected output / Dolt output:

+----+-------------+
| pk | json_column |
+----+-------------+
| 8  | [37,42]     |
| 7  | [33,51]     |
| 2  | [38,37]     |
| 4  | [17,42]     |
| 6  | [81,33]     |
+----+-------------+

GMS output:

+----+----+-------------+---------------+
| pk | v1 | json_column | vector_column |
+----+----+-------------+---------------+
| 8  | 7  | [37,42]     | B(B           |
| 7  | 7  | [33,51]     | BLB           |
| 2  | 3  | [38,37]     | BB            |
| 4  | 5  | [17,42]     | �A(B          |
| 6  | 6  | [81,33]     | �BB           |
+----+----+-------------+---------------+