Openlayers types

[simonseyock]

FEATURE | BUGFIX

This PR introduces the @hanreev/ol-types package and fixes all openlayers typing errors.

[simonseyock]

One thing that should get checked, are the attributions. But this is unrelated to this PR, see #1962

I used the public function getUid instead of the private properties ol_uid.

I fixed the types of the timeLayerAware function. There is now an correctly typed Option.

For the type ArrayTwoOrMore I introduced a type guard isArrayTwoOrMore that let you easily verify that an array is indeed of the type ArrayTwoOrMore.

Another new type guard is isWmsLayer which verifies that a generic Layer is a BaseTileLayer|BaseImageLayer.

[simonseyock]

I reverted the changes related to the selects.

[KaiVolland]

Nice one. Ol types would be very cool if they are up to date.
Please have a look the import statements to have the Ol prefix.

Even if the changes are mostly about typing i think they introduce api changes, so we have to release a major version (which is not negative).

[simonseyock]

One thing about actuality of the types: They should change only in details on minor version changes of openlayers. The hanreev types base for now on ol v6.4 but I do not think this is something we need to worry about as we are only using ol v6.5 for now.

On the next major version jump we would need to look at it again, but I am working on type improvements in the openlayers jsdoc types that will make the auto generated types usable in our projects. The hanreev types are way better, as they provide more details, for example they type the events that will be passed to the listeners.

[ahennr]

Nice work @simonseyock .

[annarieger]

Nice one, thanks for this.

I've added some notes which you maybe want to address.

[dnlkoch]

Very nice @simonseyock, I just addressed some minor issues regarding our current naming conventions and a note about moving code to separate packages.

[KaiVolland]

Thanks for the productive discussion and your effort in this. Feel free to merge once the ci is happy.