<gloss> (and presumably <desc>) content should be space-normalized

[sydb]

Per #2619, a trailing (or presumably, leading) space in a <gloss> shows up in the output. (Which output?) If so, I submit there is somewhere where we should be calling normalize-space() that we are not.

(Note: I have not added a “conversion: [whatever]” label because I do not know which output(s) are problematic.)