prevent polynomial regular expression used on uncontrolled data secur…

[ewaostrowska]

Description of the PR

• replaceAll uses a backtracking engine. The pattern ([A-Z]+)([A-Z][a-z][a-z]+) had a greedy quantified group ([A-Z]+) followed by another subpattern that starts with an overlapping class [A-Z] and then [a-z][a-z]+. Inputs like "A...A a...a" (many uppercase, then many lowercase) could have had caused an issue.
• String.replaceAll did compile the regex on each call. Using Pattern allows to compile regex once and reuse it.

The outcome of the method should be the same