Enhance tiled map API

[zacharycarter]

Tiled map API is very basic.

Add additional procs for -
know / get the size (AABB)
translate it on render?

Also -
provide way to render w/o calling begin and end on spritebatch

[zacharycarter]

proc newTiledMapComponent*(): TiledMapComponent =
    return TiledMapComponent()

proc source*(self: TiledMapComponent): TiledMap =
    return self.source

proc `source=`*(self: TiledMapComponent, value: TiledMap) =
    self.source = value
    # when the user changes the tiledmap, recalculate its bounds
    self.markAabbDirty()

method calcAabb*(self: TiledMapComponent): Rectangle =

    if self.source == nil:
        # 0,0,0,0
        return

    # TODO: calculate the total size
    return Rectangle(
        x: 0, y: 0,
        width: 1000,
        height: 1000
    )

method render*(self: TiledMapComponent, context: RenderContext) =

    if self.source == nil:
        return

    let position = absolutePosition(self.node)

    # hack
    context.batch.`end`()

    # TODO: translate the map
    self.source.render(context.batch, context.camera)

    context.batch.begin()