In theory this can replace all other API.

We can access that API without a token.

appending "#debug" to the URL enables it again. Not sure if this
the best mechanism, but better than spaming the console for now.

Pull out nextcloudfilepicker styles to file-handling styles, styling, translation and function of clipboard

Instead of handling the visibility checks at render time we keep around a list
of visible routes and emit an event when they change. This way the welcome activity
can mirror what the menu shows and update at the same time.

Setting auth/token in <dbp-components> directly without <dbp-provider>

See issue #49

Dispatch dbp-set-property event to parent (if any) so that current element doesn't terminate event if it has the attribute set itself (#48)