Fix change node to return boolean if asked

[dceejay]

to fix #4372

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Proposed changes

As per Issue #4372 if asked to replace something with a boolean - currently if the search criteria is a regex then it returns as a string - (if the search is just a string then it returns a boolean correctly). This fix forces the replacement to be a boolean if requested.

As it is a slight change in behaviour I have left it on the 4.0 dev branch - but I think as it already half works then this is more of a bug fix tbh.

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the forum/slack team.
• I have run npm run test to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality