backend: fix SQL expand of pool query for tags
backend: fix SQL expand of pool query for tags

Match and handle the equals_any operator correctly when expanding
dictSQL to SQL so that we can use it for matching on tags!

Fixes #774.

fredsod/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,garberg/NIPAP,ettrig/NIPAP,bbaja42/NIPAP,garberg/NIPAP,bbaja42/NIPAP,garberg/NIPAP,fredsod/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,ettrig/NIPAP,fredsod/NIPAP,SpriteLink/NIPAP,SoundGoof/NIPAP,SoundGoof/NIPAP,bbaja42/NIPAP,fredsod/NIPAP,SoundGoof/NIPAP,SpriteLink/NIPAP,SpriteLink/NIPAP,SoundGoof/NIPAP,SoundGoof/NIPAP,fredsod/NIPAP,fredsod/NIPAP,SpriteLink/NIPAP,garberg/NIPAP,SpriteLink/NIPAP,SoundGoof/NIPAP,bbaja42/NIPAP,ettrig/NIPAP,garberg/NIPAP,ettrig/NIPAP