conditional dynamical import of cesium view or openlayers view based on mapMode used

due to some limitations, it will be easiest to have a bundle split into two parts, one loaded always and second (built as 1.1.js) (cesium + cesiummapview) conditionally only if enable3D config is true and mapMode === '3D' Size-wise both are similar size (9 and 11mb uncompressed)

Two new configs added to each dem client:

"enable3D": true, controls if client will be allowing 3d (if switch button will be displayed)

"mapMode": '3D', in case enable3D is true, decides if initial client load will be into cesium or openlayers - button changes between the two modes and mode is saved to url if different from configured one