[SPARK-2395][SQL] Optimize common LIKE patterns.

I'll also note that this is not meant to be exaustive, but only cover some common cases that we can speed up 10x

Hive does the same thing: https://github.com/apache/hive/blob/590c37f075def63e8507f2bfca820308b40e78b3/ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/FilterStringColLikeStringScalar.java#L64