It's a bad practice to design strings with trailing and leading whitespace:

• it's too error prone
• translations look ugly or even break in other languages (specially when syntax is not the same as in english)

See related discussion: https://lang.moodle.org/mod/forum/discuss.php?d=7657

I suggest to forbid such leading and trailing spaces in Moodle strings, and propose to amend the Coding Style documentation page to clarify this and add an example (BAD/GOOD) after "Language strings > Structure", under (new) "Language strings > Leading and trailing spaces": https://docs.moodle.org/dev/Coding_style#Language_strings.