tdf#160478: fix Basic LIKE operator

tdf#160478: fix Basic LIKE operator

1. The regex must match the whole input. Thus, the ^ and $ metacharacters
   must be replaced with \A and \z, which only match beginning and end of
   input, not any line start / end.
2. The * and ? metacharacters of LIKE must match newline character; thus,
   search flags must include UREGEX_DOTALL. To avoid changing TextSearch
   implementation, I use icu::RegexMatcher directly.

The direct use of icu::RegexMatcher also allowed to simplify the code by
calling icu::RegexMatcher::matches method.  This may perform better than
general-purpose utl::TextSearch::SearchForward.

Change-Id: I75776498b36f236da294462362ed5b36ed8cdf68
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/165700
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>