Issues with injecting custom MapPopover

Hi,

I am trying to modify the default tooltip of kepler.gl, came across [this](https://github.com/keplergl/kepler.gl/issues/616) issue.

Along the lines of [custom map-control](https://github.com/keplergl/kepler.gl/blob/master/examples/demo-app/src/factories/map-control.js) implementation, I tried implementing the same for `MapPopoverFactory`.

I encountered some errors attached here
[error.txt](https://github.com/keplergl/kepler.gl/files/4185427/error.txt)

Since I'm working with master branch of kepler.gl, I could dig a little deeper to find that [`layerInfoProp` isn't being rendered](https://github.com/keplergl/kepler.gl/blob/master/src/components/map/map-popover.js#L177), and substituting it with a `

some text

In the same file, [line 82](https://github.com/keplergl/kepler.gl/blob/master/src/components/map/map-popover.js#L82). Does this have something to do with the default parameters of the factory?

Start with examples/demo-app/src/factories/map-control.js and src/components/map/map-popover.js, especially the MapPopoverFactory usage near line 82 and layerInfoProp near line 177. Reproduce the reported custom MapPopover errors from error.txt, then determine why layerInfoProp is not rendered and verify the corrected injection behavior.

Written by the indexing model from the issue text.