chore(sonar): second sweep — catch .Length, Is.Not.Empty, and newly-exposed Multiple groups (NUnit2046, NUnit2045)

Re-runs `dotnet format analyzers --diagnostics NUnit2046 NUnit2045` after
the Tier 2 Assert.Multiple wrap, which exposed:

- `Has.Length.EqualTo(n)` rewrites for `string[]`/array `.Length` checks
  (the first pass only knew about `.Count`).
- `Is.Not.Empty` rewrites for `Count, Is.GreaterThan(0)`.
- A handful of new NUnit2045 groups that became wrappable once the
  initial Multiple blocks settled the surrounding indentation.

Tests still 1180/1180 passing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/Strata.SqlTools.PostgreSql.Tests/PostgreSql/QueryBreakdownCollectionTests.cs

@@ -39,7 +39,7 @@ public class QueryBreakdownCollectionTests
         _collection.Add(query);
 
         // Assert
-        Assert.That(_collection.Count, Is.GreaterThan(0));
+        Assert.That(_collection, Is.Not.Empty);
     }
 
     [Test]
@@ -186,7 +186,7 @@ public class QueryBreakdownCollectionTests
         {
             // Assert
             Assert.That(result, Is.True);
-            Assert.That(_collection.Count, Is.GreaterThan(0));
+            Assert.That(_collection, Is.Not.Empty);
         });
     }
 
@@ -206,7 +206,7 @@ public class QueryBreakdownCollectionTests
         {
             // Assert
             Assert.That(result, Is.True);
-            Assert.That(_collection.Count, Is.GreaterThan(0));
+            Assert.That(_collection, Is.Not.Empty);
         });
     }