_setResolution(newResolution) {
    if (newResolution === this.currentResolution) {
      return;
    }

    this.currentResolution = newResolution;
    this.updateContentSize();
    this.pswp.dispatch('resolutionChanged');
  }
Set resolution and re-render the image.

For example, if the real image size is 2000x1500,
and resolution is 0.5 - it will be rendered as 1000x750.

Image with zoom level 2 and resolution 0.5 is
the same as image with zoom level 1 and resolution 1.

Used to optimize animations and make
sure that browser renders image in the highest quality.
Also used by responsive images to load the correct one.

@param {number} newResolution