allow automatic entity merging of state, style and view

[effervescentia]

within a module, state, style, and view entities with the same name will automatically be merged together and can be used as one:

state ABC {
  x: number;
}
view ABC -> <div>{$x}</div>

style DEF {
  x: {
    color: red;
  }
}
view DEF -> <header(.x) />

state GHI {
  z: string;
}
style GHI {
  y: {
    fontSize: em(2)
  }
}

view SomeView ~ GHI -> <div(.y)>{$z}</div>