Italian translation and other localization fixes

[HebaruSan]

Changes

This is the next dump from Crowdin, created by downloading the ZIP and merging it into my local CKAN source repo. (Somewhat complicated by the fact that Crowdin's "Skip untranslated files" option skips files with less than 100% translated strings.)

• @frankieorabona has graciously contributed an Italian translation!
• @WujekFoliarz has updated many of the Polish strings
• @vinix38 has updated many of the French strings
• Forum user Kalessin1 reported that the Cached filter doesn't work in Polish. This happens because the "is:cached" string was translated with spaces, which aren't allowed there because spaces delimit separate search terms. Now the space are replaced with dashes.
  (I tried to find a way to flag these strings on Crowdin so they could be validated automatically, but I wasn't able to find the custom QA check settings that the help pages claimed exist, so I ended up making a "No Spaces" label instead and applying it to these strings as a clue to translators. The only other occurrence of this was in the unreleased Italian translation, so I just fixed the initial string.)
• The unnecssary Japanese translation of HintTextBox.resx is removed

I'll self-review this because it's just l10n strings.