feature: Implement App Config v2

[matbmapspeople]

This merge request skips logic to deal with mapboxAccessToken or gmKey.

It should cover: language, primaryColor, logo, venue, startZoomLevel, pitch and bearing props.

In order to make primaryColor and logo work, I needed to remove their default values from MapsIndoorsMap.jsx and add them to MapTemplate.jsx. It is because we need to follow a proper priority: URL prop > App Config > default value (in this case)

[matbmapspeople]

@ammapspeople I just figured out that there is no work to be done for Mapbox/Google Maps API keys. When @andreeaceachir142 removes default ones from the buckets, we either set up one from URL or App Config:

[ammapspeople]

Can we think of any general way to get a value when investigating the "prop > app config > default" chain?

[matbmapspeople]

I have addressed your comments @ammapspeople