Consolidate cte_quoted_reference.slt into cte.slt (#19862)

- Merged CTE reference resolution tests into main cte.slt file
- Added CREATE TABLE statement for orders table used in tests
- Fixed 3 case-sensitivity issues: changed 'WHERE N < 10' to 'WHERE n <
10'

Fixes #19786

## Which issue does this PR close?

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- Closes #19786

## Rationale for this change

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in the issue then this section is not needed.
Explaining clearly why changes are proposed helps reviewers understand
your changes and offer better suggestions for fixes.
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This PR consolidates the small test file `cte_quoted_reference.slt` into
the main `cte.slt` file as requested in issue #19786. The separate file
was small enough that it didn't need to be maintained independently, and
consolidating it improves code organization and maintainability.

## What changes are included in this PR?

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There is no need to duplicate the description in the issue here but it
is sometimes worth providing a summary of the individual changes in this
PR.
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- Merged CTE reference resolution tests from `cte_quoted_reference.slt`
into `cte.slt`
- Added `CREATE TABLE orders AS VALUES (1), (2);` statement to support
the merged tests
- Fixed 3 pre-existing case-sensitivity bugs by changing `WHERE N < 10`
to `WHERE n < 10` in recursive CTE tests
- Deleted `cte_quoted_reference.slt` as it's now consolidated into the
main file

## Are these changes tested?

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Yes, all changes are tested:
- The consolidated tests from `cte_quoted_reference.slt` are now part of
the `cte.slt` test suite
- All sqllogictest tests pass successfully: `cargo test --test
sqllogictests -- cte`
- The case-sensitivity fixes ensure that field references match their
definitions (lowercase `n`)


## Are there any user-facing changes?

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updated before approving the PR.
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No, there are no user-facing changes. This is purely a test file
reorganization that improves code maintainability without affecting
DataFusion's functionality or API.


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Co-authored-by: Anjali Choudhary <anjalicy@amazon.com>

Author: AnjaliChoudhary99

datafusion/sqllogictest/test_files/cte.slt

@@ -42,6 +42,63 @@ physical_plan
 statement error DataFusion error: Error during planning: WITH query name "a" specified more than once
 WITH a AS (SELECT 1), a AS (SELECT 2) SELECT * FROM a;
 
+statement ok
+CREATE TABLE orders AS VALUES (1), (2);
+
+##########
+## CTE Reference Resolution
+##########
+
+# These tests exercise CTE reference resolution with and without identifier
+# normalization. The session is configured with a strict catalog/schema provider
+# (see `datafusion/sqllogictest/src/test_context.rs`) that only provides the
+# `orders` table and panics on any unexpected table lookup.
+#
+# This makes it observable if DataFusion incorrectly treats a CTE reference as a
+# catalog lookup.
+#
+# Refs: https://github.com/apache/datafusion/issues/18932
+#
+# NOTE: This test relies on a strict catalog/schema provider registered in
+# `datafusion/sqllogictest/src/test_context.rs` that provides only the `orders`
+# table and panics on unexpected lookups.
+
+statement ok
+set datafusion.sql_parser.enable_ident_normalization = true;
+
+query I
+with barbaz as (select * from orders) select * from "barbaz";
+----
+1
+2
+
+query I
+with BarBaz as (select * from orders) select * from "barbaz";
+----
+1
+2
+
+query I
+with barbaz as (select * from orders) select * from barbaz;
+----
+1
+2
+
+statement ok
+set datafusion.sql_parser.enable_ident_normalization = false;
+
+query I
+with barbaz as (select * from orders) select * from "barbaz";
+----
+1
+2
+
+query I
+with barbaz as (select * from orders) select * from barbaz;
+----
+1
+2
+
 # Test disabling recursive CTE
 statement ok
 set datafusion.execution.enable_recursive_ctes = false;
@@ -996,7 +1053,7 @@ query TT
 explain WITH RECURSIVE numbers AS (
   select 1 as n
   UNION ALL
-  select n + 1 FROM numbers WHERE N < 10
+  select n + 1 FROM numbers WHERE n < 10
 ) select * from numbers;
 ----
 logical_plan
@@ -1021,7 +1078,7 @@ query TT
 explain WITH RECURSIVE numbers AS (
   select 1 as n
   UNION ALL
-  select n + 1 FROM numbers WHERE N < 10
+  select n + 1 FROM numbers WHERE n < 10
 ) select * from numbers;
 ----
 logical_plan
@@ -1160,5 +1217,5 @@ query error DataFusion error: This feature is not implemented: Recursive CTEs ar
 explain WITH RECURSIVE numbers AS (
   select 1 as n
   UNION ALL
-  select n + 1 FROM numbers WHERE N < 10
+  select n + 1 FROM numbers WHERE n < 10
 ) select * from numbers;