Drop trailing spaces and tabs from .properties strings

[eemeli]

As discussed in bug 1900765, trailing spaces in .properties strings are currently trimmed when the file is parsed for formatting. To allow for that trimming to be dropped, the localized messages with trailing spaces should be trimmed. (And also the one translated es-ES string with a trailing tab.)

This PR does not touch the 1355 messages that end with an explicit \u0020, most (but not all!) of which are likely mistakes as well, coming from en-US strings that had trailing whitespace.

This PR touches 139 locales, which Pontoon will need to sync.

[eemeli]

If this needs to be rebased/recreated, these are the commands I used to create the diff:

git grep '^[^#].* $' -- '*.properties' | grep -v '= $' | cut -d: -f1 | sort -u | xargs gsed -i 's/ \+$//'
git grep -l '^[^#].*\t$' -- '*.properties' | xargs gsed -i 's/\t\+$//'

[flodolo]

This PR does not touch the 1355 messages that end with an explicit \u0020, most (but not all!) of which are likely mistakes as well, coming from en-US strings that had trailing whitespace.

So many strings. Is Pontoon adding those when the translation has trailing spaces? How did we end up with some translations having trailing spaces, other having \u0020, and others a combination of both?

Worth noting that:

• We still have a string with explicit trailing space.
• We asked devs to use that and not a space because it's very likely that a new dev (and their editor) will trim them at some point.