Evaluate LHS subqueries once

[howenyap]

Description

Closes #5152

When parsing where clauses in the planner, BETWEEN statements are expanded into two comparisons. This results in LHS being cloned, and later evaluated twice.

My initial idea of a fix is to add a guard to avoid expanding BETWEEN statements if the LHS is a subquery, but this still evaluates LHS twice if the subquery is nested, so I chose to walk the LHS and check whether any subqueries exist in any level instead.

The expr_contains_subquery function was copied from here by @PThorpe92.

Testing

Before adding the fix, I've added a snapshot test that shows the query plan as:

QUERY PLAN
|--SCALAR SUBQUERY 1
|  `--SCAN products
|--SCALAR SUBQUERY 2
|  `--SCAN products
`--SCAN products

After the fix, the new query plan reflects only evaluating the subquery once:

QUERY PLAN
|--SCALAR SUBQUERY 1
|  `--SCAN products
`--SCAN products

Description of AI Usage

Codex was used to explore the codebase and write most of the code, all code was manually reviewd.

[github-actions]

Fossier: Manual Review Requested

@howenyap is a new contributor. A maintainer should review this PR before merging.

Score Breakdown

Total Score: 51.2/100 | Confidence: 100% | Outcome: REVIEW

Signal	Value	Score	Weight
account_age	1429	1.00	0.07
public_repos	43	1.00	0.04
contribution_history	43	0.21	0.04
follower_ratio	0.42	0.21	0.04
bot_signals	False	0.50	0.03
open_prs_elsewhere	7	0.12	0.07
closed_prs_elsewhere	9	0.10	0.08
merged_prs_elsewhere	34	1.00	0.06
prior_interaction	1	0.33	0.24
activity_velocity	1	1.00	0.06
pr_content	...	1.00	0.06
commit_email	no_email	0.50	0.03
pr_description	...	0.80	0.04
repo_stars	19049	0.30	0.03
org_membership	0	0.20	0.02
commit_verification	...	0.30	0.03
contributor_stars	9	0.18	0.03

[github-actions]

Fossier: Manual Review Requested

@howenyap is a new contributor. A maintainer should review this PR before merging.

Score Breakdown

Total Score: 51.2/100 | Confidence: 100% | Outcome: REVIEW

Signal	Value	Score	Weight
account_age	1429	1.00	0.07
public_repos	43	1.00	0.04
contribution_history	43	0.21	0.04
follower_ratio	0.42	0.21	0.04
bot_signals	False	0.50	0.03
open_prs_elsewhere	7	0.12	0.07
closed_prs_elsewhere	9	0.10	0.08
merged_prs_elsewhere	34	1.00	0.06
prior_interaction	1	0.33	0.24
activity_velocity	1	1.00	0.06
pr_content	...	1.00	0.06
commit_email	no_email	0.50	0.03
pr_description	...	0.80	0.04
repo_stars	19049	0.30	0.03
org_membership	0	0.20	0.02
commit_verification	...	0.30	0.03
contributor_stars	9	0.18	0.03