Support new map styling

[cnouguier]

We'd like to support our own style specification :

style: {
  // Line geometry
  line: {
    color: primary,
    width: 1,
    opacity: 1.0,
    cap: 'round', // https://developer.mozilla.org/fr/docs/Web/SVG/Attribute/stroke-linecap
    join: 'round', // https://developer.mozilla.org/fr/docs/Web/SVG/Attribute/stroke-linejoin
    dashArray: 'none',
    dashOffset: 0
  },
  // Polygon geometry
  polygon: {
    color: primary,
    opacity: 1.0,
    fillRule: 'evenodd' // https://developer.mozilla.org/fr/docs/Web/SVG/Attribute/fill-rule
    stroke: {
        color: primary,
        width: 1,
        opacity: 1.0,
        cap: 'round', // https://developer.mozilla.org/fr/docs/Web/SVG/Attribute/stroke-linecap
        join: 'round', // https://developer.mozilla.org/fr/docs/Web/SVG/Attribute/stroke-linejoin
        dashArray: 'none',
        dashOffset: 0
    }
  },
  // Point geometry
  marker: {
    shape: 'circle',
    size: ['24px', '24px'],
    radius: undefined, 
    color: primary
    opacity: 1.0,
    stroke: { 
        color: primary,
        width: 1,
        opacity: 1.0,
        cap: 'round', // https://developer.mozilla.org/fr/docs/Web/SVG/Attribute/stroke-linecap
        join: 'round', // https://developer.mozilla.org/fr/docs/Web/SVG/Attribute/stroke-linejoin
        dashArray: 'none',
        dashOffset: 0
    },
    icon: {
      classes: undefined // must be specified
      url: ''
      color: 'black',
      opacity: 1.0,
      size: '14px',
      translation: ['-50%', '-50%'],
      rotation: 0
    },
    text: {
      label: undefined, // must be specified
      color: 'black',
      size: '12px',
      translation: ['-50%', '-50%'],
      rotation: 0
    },
   htmlt: null
  }
}

We still need to support simplespec style for backward compatibility