For
https://gerrit.wikimedia.org/r/#/c/197357/ I'd like to move some bits of the WikiEditor extension into MediaWiki core, so that we can re-use them in VisualEditor. That would involve moving the 19 wikieditor-toolbar-characters-page-* i18n messages and renaming their keys, while preserving all of their translations. Is this possible? If so, what is the process?