[WIP] fix map interaction

[lucernae]

A series of fix and refactor for GeoNode Map interaction for QGIS Server Backend.

Related issues

#207 - Fix map interaction
#407 - Get add layer to map
#359 - Map update thumbnail not working
#367 - Background layer does not work in map create page
#456 - Fix create map default extent
#489 - Wrong map extent when using different CRS
#525 - Reset map thumbnail doesn't work
#528 - Current Map View page is unmanageable and need refactor
#406 - Layer symbology not working as expected

Interaction list that needs to be fixed:

• Fix Map Create Page functionality
• Fix Map Update Page functionality
• Fix Create Map from Layer Detail
• Fix Create Map from Duplicate Map button
• Add basemap to map thumbnail
• Fix projection in thumbnail and map view
• Refactor unused dead code
• Fix set thumbnail functionality
• Fix Map Detail Page functionality

[lucernae]

Demonstrated here:

• Create new page at first will zoom out to world: fix fix create map default extent #456
• UI change to use proper bootstrap (it can be extended later if not satisfied)
• Layer list loaded via AJAX request --> Map page load faster first, then load layer lists
• UI Feedback when layer is saved. Also options to go to map detail or list or stay in creation page.
• Take basemap options list from LEAFLET settings (the same list in Layer view page). Fix background layers don't load properly in Create a New Map #367
• Thumbnail now with chosen basemap
• Fix Wrong map extent for maps using layers with different CRS #489
• Layer symbology follow default styles defined in the layer itself. fix Layer symbology differs from the one in thumbnails generated on map creation #406

[lucernae]

Demonstrated here:

• Updating/changing existing Map
• Add remove existing map layer in a map
• Change layer order
• Change basemap
• Change title/abstract
• Note that I haven't fixed Map Detail page yet, so the layer order in that page is a mess.
• New thumbnail works with correct order and basemap