Script Loader: Add translator comments and remove textdomains.

The inline script for `wp-date` incorrectly included a textdomain, and lacked translator comments.

Merges [43831] from the 5.0 branch to trunk.

Props mukesh27.
Fixes #45191, #45162.


Built from https://develop.svn.wordpress.org/trunk@44171


git-svn-id: https://core.svn.wordpress.org/trunk@44001 1a063a9b-81f0-0310-95a4-ce76da25c4cd