This will help making sure that the view will come back to a "rested" state
once the interactions are over.
Interactions no longer need to handle the animation back to a rested state,
they simply call `endInteraction` with the desired duration and direction.
This commit aims to simplify the computation of zoom and resolution in the
View class.
Previously zoom levels and resolution computations were mixed in different places,
ie resolution constraints, initial values, etc.
Now the View class only has the `getZoomForResolution` and `getResolutionForZoom`
methods to convert from one system to another.
Other than that, most computations use the resolution system internally.
The `constrainResolution` method also does not exist anymore, and is replaced
by `getValidResolution` and `getValidZoomLevel` public methods.
This introduces a breaking change:
The `extent` view option now constrains the whole viewport and not just the
view center.
The option `constrainOnlyCenter` was added to keep the previous behaviour.
Constraining the whole viewport and not only the view center means
that the center and resolution constraints must be applied with a knowledge of
the viewport size.
The `getValidZoomLevel` apply the current resolution constraint to return
a value that is guaranteed valid.
This is used for interactions & controls which need a target value to work:
the +/- buttons, the zoom clider, the dragbox zoom and the mouse wheel zoom.
- Rename linearRingIsOriented => linearRingsAreOriented
The function checks all linear rings of a Polygon, so
the plural "rings" is more appropriate
- Rename linearRingsAreOriented => linearRingssAreOriented
The double s is appropriate because the check is done for
all Polygons of a MultiPolygon
This commit restores the function names from OpenLayers v4,
they were changed (wrongly IMHO) in #7820.
