Rename "legacy juggler bridge" mentioned in docs #5558
Description
From our last maintainer's call, @mitsos1os suggested that the term "legacy juggler bridge" might give the wrong impression to users that the juggler won't be supported or not working well because of the "legacy" word.
@bschrammIBM (our technical writer previously) had made a similar comment.
Acceptance Criteria
- go through the occurrences of "legacy juggler bridge", rename it to simply "juggler bridge" if applicable. See search results: https://github.com/strongloop/loopback-next/search?p=1&q=%22legacy+juggler%22&unscoped_q=%22legacy+juggler%22
- go through codebase and make sure "legacy" is not used anymore.