[ticket/11288] Handle +,- without preceeding whitespace characters

PHPBB3-11288
Merge branch 'ticket/11288' into ticket/11288-develop

* ticket/11288:
  [ticket/11288] Handle +,- without preceeding whitespace characters
[ticket/11288] Add unit test cases for foo-bar like queries

foo-bar and foo -bar are interpreted differently by
native search backend now.

PHPBB3-11288