Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
Moves the logic into the SCH_RENDER_SETTINGS, rather than
repeating it in EESCHEMA/SYMBOL_EDITOR_SETTINGS (they still
maintain their state there, but the painter looks at the
SCH_RENDER_SETTINGS).
Also turn them off for preview purposes.
Actually add a whole new panel for symbol editor appearance control.
Use the SYMBOL_EDITOR_SETTINGS as the source of truth in a
couple more places, but the SCH_PAINTER settings are still
driving quite a bit here and there.
Fixes: https://gitlab.com/kicad/code/kicad/-/issues/18830
Remove some useless spacers, and do not force some widgets to have a to
large size (by removing empty areas).
Work in progress: one panel is still too big.
