Minor QRegularExpression optimisations
- More static const QRegularexpression objects, where the pattern is known at compile time, this way the regex won't need to be reparsed
- Make capture groups non-capturing, or remove the "()" altogether where appropriate, less book-keeping on the PCRE engine side
- Make QRegularExpressionMatch objects const where appropriate
- "\w{1,}" is "\w+"
Unit tests still pass.