fix handlebars i18n/wrapper/whitespace bug, closes CNVS-11638

refs CNVS-11421

no way to quote a newline in a literal handlebars params/option, and
unescaping it after the fact seems grody. luckily whitespace isn't
significant, so we can just smush it all into a space.

test plan:
* see specs
* also, confirm that there's no \n on that scheduler page (see CNVS-11421)

Change-Id: Icb0753a6bf4248ed051d5e01ebdcdae17360b773
Reviewed-on: https://gerrit.instructure.com/31339
Reviewed-by: Jon Jensen <jon@instructure.com>
QA-Review: Jon Jensen <jon@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Jon Jensen <jon@instructure.com>