[filter_box] allow empty filters list (#7220) (#7244)
[filter_box] allow empty filters list (#7220) (#7244)

in some cases, people want a time filter only on filter box, without
specifying dimensions (filters), this allows that

(cherry picked from commit e39b16994946b2a7975af3ed76245e77303329e2)
mistercrunch/panoramix,airbnb/caravel,zhouyao1994/incubator-superset,airbnb/superset,mistercrunch/panoramix,airbnb/caravel,airbnb/caravel,airbnb/superset,apache/incubator-superset,zhouyao1994/incubator-superset,zhouyao1994/incubator-superset,airbnb/superset,zhouyao1994/incubator-superset,apache/incubator-superset,apache/incubator-superset,airbnb/superset,zhouyao1994/incubator-superset,mistercrunch/panoramix,airbnb/caravel,mistercrunch/panoramix,apache/incubator-superset,apache/incubator-superset