[ci skip] Fix HTML format on comment
Merge pull request #18081 from yui-knk/fix/capture_helper

[ci skip] Fix HTML format on comment
Relax the UUID regex

Apparently PG does not validate against RFC 4122. The intent of the original
patch is just to protect against PG errors (which potentially breaks txns, etc)
because of bad user input, so we shouldn't try any harder than PG itself.

Closes #17931
adds another examle to the constants not missing gotcha [ci skip]

/cc @matthewd
passed a spell checker, not bad [ci skip]
Allow precision option for PostgreSQL and MySQL datetimes and times.