Add analyzer that catches properties that can be made readonly

Version Used:

Steps to Reproduce:

It would be nice to have an analyzer that catches that the following property can be made readonly. Hit this on a PR just recently.

    public class Foo
    {
        public Foo(string property)
        {
            Property = property;
        }
        
        private string Property
        {
            get;
            set;  // <!-- Can remove
        }

        public void Method()
        {
            Console.WriteLine(Property);
        }
    }