Speed up like_utf8_scalar for %pat%

[Dandandan]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
Currently there is no special case for like patterns such as %pat%. We should add a special case that uses contains instead, which likely is faster than the regex parser.

Describe the solution you'd like

Describe alternatives you've considered

Check whether the like pattern only contains a pattern starting and ending with a wildcard, use contains for those instead.

Additional context

Make sure to run the benchmarks.