style: Move moz-control-character-visibility out of mako, and remove support for gecko_pref_controlled_initial_value

No behavior change, just cleanup. Actually seem this technically _adds_ some code even
though it's a cleanup, but that's mostly because of the wrapping of the
derive list.  The resulting code is simpler (more in-line with our usual
things, so I think it's an improvement).

Differential Revision: https://phabricator.services.mozilla.com/D111551

components/style/properties/data.py

@@ -483,6 +483,7 @@ class Longhand(Property):
                 "LineBreak",
                 "MasonryAutoFlow",
                 "MozForceBrokenImageIcon",
+                "text::MozControlCharacterVisibility",
                 "MozListReversed",
                 "MathDepth",
                 "MozScriptMinSize",