filter-utils.lua: Check media type when finding the default filter
This MR fixes the get_filter_from_target()
API from filter-utils.lua
so that it does not return an audio filter for video targets. This avoids WirePlumber trying to link a video stream node with the default audio smart filter if smart audio filters are configured.
The fix adds a media_type
param in the get_filter_from_target()
API to make sure the desired type of filter is returned. The rest of APIs don't need such media_type
param because they already have the link_group
param, which is unique for all filters (both audio and video).