x11/xmoji: Update to 0.8

New upstream release. Changes:

• Add tooling for localized UI texts and Emoji names imported from Unicode CLDR
• Add translations for German (de)
• Improve search, show groups (skin-tone variants of the same Emoji) in search results and make it configurable what exactly the search looks at: original and/or translated names, and whether or not to consider other "variant" descriptions after a colon in the name
• Implement the _NET_WM_PING protocol and associated window properties, allowing a window manager to know when and how to force-kill Xmoji