Merge pull request #1513 from elemoine/vector-api-docs

[vector-api] ol.source.ImageVector improvements
Create 'type' annotation for 'const' variables
Merge pull request #1515 from fredj/vector-api-const-annotation

[vector-api] Create 'type' annotation for 'const' variables
Hit detection refactoring

Get the frame state from the map instead of storing values in the layer renderers.