Persist routes across style changes

[LukasPaczos]

This PR fixes #2039 by caching the currently drawn routes/waypoints and reusing those same geometries immediately when the new style is loaded.

As you can see, the transitions are smooth, besides the first style change after NavigationMapRoute creation. @pozdnyakov and I are looking into the root cause.

[pozdnyakov]

The issue is caused with style changes handling logic in mapbox-gl-native: atm it is considering sources order of the style, meaning that if the sources order of the updated style differs from the current sources order some sources are removed and re-added => flickering is observed. The preliminary fix is here I'm going to make it more elegant and shortly make a PR to the mapbox-gl-native repo with the appropriate fix.

[LukasPaczos]

This is ready for review, but we cannot merge until @pozdnyakov's fix is available in a Map SDK's patch.

[codecov-io]

Codecov Report

Merging #2262 into master will increase coverage by 0.05%.
The diff coverage is 57.89%.

@@             Coverage Diff              @@
##             master    #2262      +/-   ##
============================================
+ Coverage     32.92%   32.97%   +0.05%     
- Complexity      621      627       +6     
============================================
  Files           143      143              
  Lines          5492     5519      +27     
  Branches        417      420       +3     
============================================
+ Hits           1808     1820      +12     
- Misses         3488     3505      +17     
+ Partials        196      194       -2

[pozdnyakov]

The corresponding GL-Native issue is at https://github.com/mapbox/mapbox-gl-native-team/issues/108 and the fix is at mapbox/mapbox-gl-native#15941

[Guardiola31337]

This is looking good, great work @LukasPaczos

Nice refactoring out of MapboxMap into Style 💯 ❤️

As soon as we get the Maps final release we can merge here 🚀

[LukasPaczos]

Bumped Maps version to v8.5.1.

[Guardiola31337]

Minor thing: Should we remove?

[LukasPaczos]

I left it for ease of use in the future. So that we don't have to look up the reference every time 😅