This updates ESLint and our shared eslint-config-openlayers to use Prettier. Most formatting changes were automatically applied with this:
npm run lint -- --fix
A few manual changes were required:
* In `examples/offscreen-canvas.js`, the `//eslint-disable-line` comment needed to be moved to the appropriate line to disable the error about the `'worker-loader!./offscreen-canvas.worker.js'` import.
* In `examples/webpack/exapmle-builder.js`, spaces could not be added after a couple `function`s for some reason. While editing this, I reworked `ExampleBuilder` to be a class.
* In `src/ol/format/WMSGetFeatureInfo.js`, the `// @ts-ignore` comment needed to be moved down one line so it applied to the `parsersNS` argument.
The zDirection addition to the Zoomify tile source only takes effect through
the renderer, so these two renderer cases are added to test the behavior.
zoomify-no-zdirection expects the default behavior.
zoomify-zdirection expects the tiles for the next better resolution.
