Add an environment to Modifier

[cornerman]

We want to be able to build web components that depend on an environment without passing the environment through the whole application. The ideas basically boils down to having a type parameter for Modifier/VDomModifier like Modifier[-Env].

This allows the following:

case class MyEnv(state: State, api: Api)
...

val inputField: Modifier[MyEnv] = input(
  cls := "input-field",
  Modifier.access[MyEnv](env => value := env.state.initialValue),
  Modifier.access[MyEnv](env => onChange.value.useAsync(env.api.submitChange(_))
)

// Later you can use the input field just normally or at some point, you can decide to provide the environment:
val independentInputField: Modifier[Any] = inputField.provide(MyEnv(???, ???))

This will allows us to render Kleisli or ZIO with environments. Input and ideas are always welcome!