Error generating query with nullable decimal sum

## File a bug

When handling nullability with `Sum` from `LINQ`, EfCore surrounds the `SUM` SQL command with COALESCE (for relational databases).

The problem is that EfCore always define the 'right' parameter for the coalesce as `Int` (even if the sum is resulting with decimal places).

This can cause errors generating the SQL query when you have converters, because efcore tries to pass a int to a non-int converter.

## Decimal converter

- Here's my decimal converter, with EfCore trying to pass the int from the coalesce as parameter.

### StackTrace
```
fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[1]
An unhandled exception has occurred while executing the request.
System.InvalidCastException: Unable to cast object of type 'System.Int32' to type 'System.Nullable`1[System.Decimal]'.
at Microsoft.EntityFrameworkCore.Storage.ValueConversion.ValueConverter`2.<>c__DisplayClass6_0`2.b__0(Object v)
at Microsoft.EntityFrameworkCore.Storage.RelationalTypeMapping.GenerateSqlLiteral(Object value)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitSqlConstant(SqlConstantExpression sqlConstantExpression)
at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerQuerySqlGenerator.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.b__26_0(SqlExpression e)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateList[T](IReadOnlyList`1 items, Action`1 generationAction, Action`1 joinAction)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitSqlFunction(SqlFunctionExpression sqlFunctionExpression)
at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerQuerySqlGenerator.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitProjection(ProjectionExpression projectionExpression)
at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerQuerySqlGenerator.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.b__21_0(ProjectionExpression e)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateList[T](IReadOnlyList`1 items, Action`1 generationAction, Action`1 joinAction)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitSelect(SelectExpression selectExpression)
at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerQuerySqlGenerator.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitScalarSubquery(ScalarSubqueryExpression scalarSubqueryExpression)
at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerQuerySqlGenerator.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitProjection(ProjectionExpression projectionExpression)
at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerQuerySqlGenerator.VisitExtension(Expression extensionExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.b__21_0(ProjectionExpression e)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateList[T](IReadOnlyList`1 items, Action`1 generationAction, Action`1 joinAction)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitSelect(SelectExpression selectExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateRootCommand(Expression queryExpression)
at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GetCommand(Expression queryExpression)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalCommandCache.GetRelationalCommandTemplate(IReadOnlyDictionary`2 parameters)
at Microsoft.EntityFrameworkCore.Internal.RelationCommandCacheExtensions.RentAndPopulateRelationalCommand(RelationalCommandCache relationalCommandCache, RelationalQueryContext queryContext)
at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.InitializeReaderAsync(AsyncEnumerator enumerator, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.MoveNextAsync()
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
```

## Query
My query looks something like this:

```csharp
var select = await unitOfWork.GetRepository()
.GetAll()
.Select(p => new GetProductsReadyForUseDto
{
ProductId = p.Id,
TotalBalance = p.StockMovements.Sum(m => m.Quantity),
})
.ToListAsync(cancellationToken);
```

The ‘Quantity’ property (which is nullable) has the converter, which is shown in the text below, configured for it.

### Converter

In my use case i am allowing the converter handle nulls:

```csharp
public class DecimalToDefaultConverter : ValueConverter
{
public DecimalToDefaultConverter()
: base(
v => v ?? default,
v => v == default ? null : v,
convertsNulls: true)
{
}
}
```

PS: In my case, my converter will actually change the right ‘0’ from the COALESCE into a NULL, which doesn’t make much sense (maybe the zero of the coalesce, added by EF Core, should skip the converter altogether?).

### Suggestion

It seems that EF Core uses the converter from the property present in the sum expression and applies it to the zero from the COALESCE function, which is automatically added by EF Core itself.

I think that EF Core should either prevent the right zero from the COALESCE function from being passed to the converter, or perhaps passing the proper type when creating the COALESCE would fix the issue (?).

The following code passes the type to the right side of the COALESCE function instead of letting it be inferred by the type of the value.

https://github.com/dotnet/efcore/commit/fa3214023f3f15b5b2b4b5ee80b1e203b9c318a6

### Include provider and version information

EF Core version: 8.0.6
Database provider: Microsoft.EntityFrameworkCore.SqlServer
Target framework: .NET 8.0
Operating system: MacOS
IDE: Rider