chore(sonar): wrap independent assertions in Assert.Multiple (NUnit2045)

Driven by `dotnet format analyzers --diagnostics NUnit2045`. The fixer
groups consecutive independent `Assert.That(...)` calls into
`Assert.Multiple(() => { ... })`, so a failing assertion no longer
short-circuits the block — every failure inside the group is reported,
which gives much better diagnostics on multi-property tests.

Audit confirmed no Assert.Throws / Assert.Fail / Assert.Catch / Assert.Pass
/ Assert.DoesNotThrow got pulled inside a Multiple block (those need to
short-circuit). All 1180 tests pass.

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

tests/Strata.SqlTools.Snowflake.Tests/Snowflake/StatementExpressionParserTests.cs

@@ -34,8 +34,11 @@ public class StatementExpressionParserTests
 
         // Assert
         Assert.That(result, Is.Not.Null);
-        Assert.That(result, Is.InstanceOf<NumberLiteralExpression>());
-        Assert.That(((NumberLiteralExpression)result).Value, Is.EqualTo(42));
+        Assert.Multiple(() =>
+        {
+            Assert.That(result, Is.InstanceOf<NumberLiteralExpression>());
+            Assert.That(((NumberLiteralExpression)result).Value, Is.EqualTo(42));
+        });
     }
 
     [Test]
@@ -49,8 +52,11 @@ public class StatementExpressionParserTests
 
         // Assert
         Assert.That(result, Is.Not.Null);
-        Assert.That(result, Is.InstanceOf<NumberLiteralExpression>());
-        Assert.That(((NumberLiteralExpression)result).Value, Is.EqualTo(3.14m));
+        Assert.Multiple(() =>
+        {
+            Assert.That(result, Is.InstanceOf<NumberLiteralExpression>());
+            Assert.That(((NumberLiteralExpression)result).Value, Is.EqualTo(3.14m));
+        });
     }
 
     [Test]
@@ -64,8 +70,11 @@ public class StatementExpressionParserTests
 
         // Assert
         Assert.That(result, Is.Not.Null);
-        Assert.That(result, Is.InstanceOf<ColumnExpression>());
-        Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("CUSTOMER_ID"));
+        Assert.Multiple(() =>
+        {
+            Assert.That(result, Is.InstanceOf<ColumnExpression>());
+            Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("CUSTOMER_ID"));
+        });
     }
 
     [Test]
@@ -79,8 +88,11 @@ public class StatementExpressionParserTests
 
         // Assert
         Assert.That(result, Is.Not.Null);
-        Assert.That(result, Is.InstanceOf<ColumnExpression>());
-        Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("CUSTOMER_ID"));
+        Assert.Multiple(() =>
+        {
+            Assert.That(result, Is.InstanceOf<ColumnExpression>());
+            Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("CUSTOMER_ID"));
+        });
     }
 
     #endregion
@@ -232,8 +244,11 @@ public class StatementExpressionParserTests
 
         // Assert
         Assert.That(result, Is.Not.Null);
-        Assert.That(result, Is.InstanceOf<ColumnExpression>());
-        Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("ORDER_TOTAL"));
+        Assert.Multiple(() =>
+        {
+            Assert.That(result, Is.InstanceOf<ColumnExpression>());
+            Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("ORDER_TOTAL"));
+        });
     }
 
     [Test]
@@ -247,8 +262,11 @@ public class StatementExpressionParserTests
 
         // Assert
         Assert.That(result, Is.Not.Null);
-        Assert.That(result, Is.InstanceOf<ColumnExpression>());
-        Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("NET_REVENUE_USD_2024"));
+        Assert.Multiple(() =>
+        {
+            Assert.That(result, Is.InstanceOf<ColumnExpression>());
+            Assert.That(((ColumnExpression)result).ColumnName, Is.EqualTo("NET_REVENUE_USD_2024"));
+        });
     }
 
     [Test]
@@ -368,9 +386,12 @@ public class StatementExpressionParserTests
         // Act
         var success = _parser.TryParse(sql, out var result);
 
-        // Assert
-        Assert.That(success, Is.False);
-        Assert.That(result, Is.Null);
+        Assert.Multiple(() =>
+        {
+            // Assert
+            Assert.That(success, Is.False);
+            Assert.That(result, Is.Null);
+        });
     }
 
     #endregion