[improve][doc] Improve the description of acknowledgment timeout in Java docs and REST API links

[momo-jun]

Modifications

1. Fix #16695 - improve the description of acknowledgment timeout in Java docs
2. Fix incorrect REST API links or add anchors to land on a specific REST API, especially for doc versions 2.7.x.
3. Add a new lookup REST API entry and update related two REST API links of "lookup" and "get bundle".

Documentation

• [x] doc

[momo-jun]

Ping @RobertIndie @Anonymitaet for review.