CA1062: Validate arguments of public methods

First off, I'm not sure if this project is intended to fix issues like this, but here goes.

The current version of GuardClauses does not prevent "CA1062: Validate arguments of public methods" from producing warnings.

Example that would produce the warning on modelBuilder:

```c#
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
Guard.Against.Null(modelBuilder, nameof(modelBuilder));

base.OnModelCreating(modelBuilder);

// All string properties are considered VARCHAR by default.
foreach (var property in modelBuilder.Model.GetEntityTypes().SelectMany(t => t.GetProperties()).Where(p => p.ClrType == typeof(string)))
property.AsProperty().Builder.IsUnicode(false, ConfigurationSource.Convention);
}
```

Start by reproducing the CA1062 warning for the OnModelCreating(ModelBuilder modelBuilder) example and inspect how Guard.Against.Null is recognized. Determine what analyzer behavior is needed for this pattern; done means the shown public-method argument no longer produces the warning while the existing guard call remains valid.

Written by the indexing model from the issue text.