HF RL Explorer

Backport maintenance/4.0.x Preserve falsey explicit locations in add message

Backport maintenance/4.0.x Preserve falsey explicit locations in add message: a task in repo2rlenv-v083-pr diff (Harbor dataset). Title: Backport maintenance/4.0.x Preserve falsey explicit locations in add message

The task

**Title:** [Backport maintenance/4.0.x] Preserve falsey explicit locations in ``add_message``

Part of AdithyaSK/repo2rlenv-v083-pr_diff.