Let Find/Replace dialog correctly handle unicode substrings
- strlen() returns byte count = wrong offsets for charIndexToIterator()
- Glib::ustring.length() gives proper UTF8 character count
✊ 🥳 - ( .. or how about g_utf8_strlen()? )
- ( & why sp_te_replace() don't need no ustring? )
Fixes: #1758 (closed) Seems not to fix: #1571 (closed)