backend: Add a default get_images impl.
backend: Add a default get_images impl.

ali/mopidy,quartz55/mopidy,SuperStarPL/mopidy,kingosticks/mopidy,bacontext/mopidy,bacontext/mopidy,SuperStarPL/mopidy,hkariti/mopidy,quartz55/mopidy,ZenithDK/mopidy,jodal/mopidy,pacificIT/mopidy,tkem/mopidy,ali/mopidy,kingosticks/mopidy,hkariti/mopidy,mokieyue/mopidy,hkariti/mopidy,diandiankan/mopidy,swak/mopidy,ZenithDK/mopidy,diandiankan/mopidy,rawdlite/mopidy,glogiotatidis/mopidy,swak/mopidy,vrs01/mopidy,quartz55/mopidy,jmarsik/mopidy,vrs01/mopidy,jodal/mopidy,rawdlite/mopidy,bencevans/mopidy,adamcik/mopidy,hkariti/mopidy,diandiankan/mopidy,ZenithDK/mopidy,pacificIT/mopidy,swak/mopidy,SuperStarPL/mopidy,mopidy/mopidy,dbrgn/mopidy,jmarsik/mopidy,ZenithDK/mopidy,jcass77/mopidy,jmarsik/mopidy,rawdlite/mopidy,bacontext/mopidy,ali/mopidy,vrs01/mopidy,SuperStarPL/mopidy,glogiotatidis/mopidy,glogiotatidis/mopidy,rawdlite/mopidy,jmarsik/mopidy,glogiotatidis/mopidy,ali/mopidy,mopidy/mopidy,adamcik/mopidy,mokieyue/mopidy,bencevans/mopidy,kingosticks/mopidy,jodal/mopidy,mokieyue/mopidy,pacificIT/mopidy,mopidy/mopidy,pacificIT/mopidy,tkem/mopidy,mokieyue/mopidy,bencevans/mopidy,adamcik/mopidy,swak/mopidy,quartz55/mopidy,dbrgn/mopidy,jcass77/mopidy,jcass77/mopidy,dbrgn/mopidy,vrs01/mopidy,bacontext/mopidy,diandiankan/mopidy,dbrgn/mopidy,tkem/mopidy,bencevans/mopidy,tkem/mopidy