Fix WordUtils.containsAllWords missing words across line breaks

[alhudz]

1. containsAllWords builds the per-word regex .*\b<word>\b.* and runs it with matches(), but compiles it without Pattern.DOTALL, so . never matches a line terminator.
2. matches() has to consume the whole input, so a word sitting on a different line than the surrounding .* can reach is never found.

Repro: WordUtils.containsAllWords("foo\nbar", "bar")
Expected: true (bar is present as a whole word)
Actual: false
Fix: compile the pattern with Pattern.DOTALL so the leading and trailing .* span line breaks. The \b anchors are unchanged, so single-line results and the documented examples behave the same and no false positive is introduced.

The same regex is in commons-text WordUtils.containsAllWords.

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[garydgregory]

Hello @alhudz
Please port to Apache Commons Text.
Thank you!

[alhudz]

Ported in apache/commons-text#754 — same Pattern.DOTALL fix and a matching regression test.