[UX] Wait 0.5s before showing "searching for" dialog (#7012)
[UX] Wait 0.5s before showing "searching for" dialog (#7012)

Fixes <https://github.com/koreader/koreader/issues/3030>.

Cross-ref to <https://github.com/koreader/koreader/pull/6998>.
poire-z/koreader,Markismus/koreader,poire-z/koreader,Frenzie/koreader,mwoz123/koreader,koreader/koreader,NiLuJe/koreader,pazos/koreader,Hzj-jie/koreader,koreader/koreader,Frenzie/koreader,NiLuJe/koreader