support command `\bicaption[]{<first-caption>}{<send-caption>}` in longtable

Command \caption[]{⟨caption⟩} in longtable environment makes no entry in the list of tables, so does \bicaption[]{<first-caption>}{<send-caption>}. But it makes an entry in the customising lists.

Command \bicaption*{<first-caption>}{<send-caption>} should be the same.