Merge #13726: Utils and libraries: Removes the boost/algorithm/string/join dependency

Summary:
PR13726 backport https://github.com/bitcoin/bitcoin/pull/13726/files
5f019d5354 Removes the boost/algorithm/string/join dependency (251)

Pull request description:

This commit removes the `boost/algorithm/string/join` dependency from the project by replacing `boost::algorithm::join` with the helper function proposed by @MarcoFalke in https://github.com/bitcoin/bitcoin/pull/13726#discussion_r204159967

Backporter notes:

• One line missing due to prior removal of versionbits logic.

Test Plan: make check

Reviewers: jasonbcox, Fabien, schancel, #bitcoin_abc, deadalnix

Reviewed By: jasonbcox, Fabien, #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D3381