Update addon search URIs

[avtoso]

See https://github.com/bromix/plugin.audio.soundcloud/issues/15 for context

Chorus is using outdated calls to plugins. This makes search not work in at least the SoundCloud plugin (and probably more). It gives errors like:
"Mapping for path 'Search+kodion/search/list/' not found"
"Mapping for path '/SearchTracks' not found"

AFAICT, it should be calling '/kodion/search/<...>'.