Add SimpleTable construct based on Named Tuples

[bishabosha]

This provides a SimpleTable class that extends Table, but allows to define the case class without a higher-kinded type parameter.

In turn, expressions are based on a Record class, that is structurally typed, that can convert easily back to the original case class.

In this design, there are no macros, and no transparent inline. To simplify the type gymnastics it is required for the case class to extend SimpleTable.Source. Other designs are possible e.g. #82

package scalasql.example

import scalasql.dialects.H2Dialect.*
import scalasql.namedtuples.*
import scalasql.*

case class Person(name: String, age: Int) extends SimpleTable.Source
object Person extends SimpleTable[Person]()

case class City(name: String, population: Int, mayor: Person) extends SimpleTable.Source
object City extends SimpleTable[City]()

@main def foo =
  City.select.filter(_.name === "foo").map(_.mayor)
  City.insert.values(City("foo", 42, Person("bar", 23)))
  City.insert.columns(_.name := "foo")
  City.insert.batched(_.name, _.population, _.mayor.name)(("foo", 42, "bar"), ("baz", 23, "qux"))

Inside the expressions you have the type Record[City, Expr], with structural fields