Naming vec_distance column and then referring to it in order by does not use the index

[timsehn]

Repro:

1. Clone: https://www.dolthub.com/repositories/timsehn/vector_example
2. Checkout all-MiniLM-L6-v2 branch
3. This query uses the index:

$ dolt sql -q "set @query = (select embeddings from yelp where id = 1); explain plan select id, review, vec_distance(embeddings, @query) as distance from yelp order by vec_distance(embeddings, @query) limit 3;"
+-------------------------------------------------------------------------------------------------------+
| plan                                                                                                  |
+-------------------------------------------------------------------------------------------------------+
| Limit(3)                                                                                              |
|  └─ Project                                                                                           |
|      ├─ columns: [yelp.id, yelp.review, VEC_DISTANCE_L2_SQUARED(yelp.embeddings, @query) as distance] |
|      └─ IndexedTableAccess(yelp)                                                                      |
|          ├─ index: [yelp.embeddings]                                                                  |
|          ├─ order: VEC_DISTANCE_L2_SQUARED(yelp.embeddings, @query) LIMIT 3 (bigint)                  |
|          └─ columns: [review id embeddings]                                                           |
+-------------------------------------------------------------------------------------------------------+

This query does not:

$ dolt sql -q "set @query = (select embeddings from yelp where id = 1); explain plan select id, review, vec_distance(embeddings, @query) as distance from yelp order by distance limit 3;"
+--------------------------------------------------------------------------------------------------------------------------------------------+
| plan                                                                                                                                       |
+--------------------------------------------------------------------------------------------------------------------------------------------+
| Limit(3)                                                                                                                                   |
|  └─ Project                                                                                                                                |
|      ├─ columns: [yelp.id, yelp.review, VEC_DISTANCE_L2_SQUARED(yelp.embeddings, @query) as distance]                                      |
|      └─ Sort(VEC_DISTANCE_L2_SQUARED(yelp.embeddings, @query) as distance ASC)                                                             |
|          └─ Project                                                                                                                        |
|              ├─ columns: [yelp.label, yelp.review, yelp.id, yelp.embeddings, VEC_DISTANCE_L2_SQUARED(yelp.embeddings, @query) as distance] |
|              └─ Table                                                                                                                      |
|                  ├─ name: yelp                                                                                                             |
|                  └─ columns: [label review id embeddings]                                                                                  |
+--------------------------------------------------------------------------------------------------------------------------------------------+