Add U+1E9E capital ssharp to layouts with ssharp
Some layouts which have the ssharp character somewhere (often AltGr+S), correspondingly have U+1E9E "LATIN CAPITAL LETTER SHARP S" (ẞ) on the Shift position, but this character wasn't added to many older layouts.
The attached diff capital-ssharp.diff adds U+1E9E to those layouts where there's no (useful) character present yet on the Shift layer on regular ssharp. (If there's another character there, often "section" or "question", we don't touch it.)
It does not work properly with Caps Lock though; Caps Lock doesn't turn U+00DF (ssharp) into U+1E9E. The standard German layout – which has question mark on Shift+ssharp – uses a FOUR_LEVEL_PLUS_LOCK to enter U+1E9E with Caps Lock, but we can't do that for level3 keys where most other layouts have ssharp.